Managing Corporate Sustainability and Responsibility E ﬃ ciently: A Review of Existing Literature on Business Groups and Networks

: Given the global relevance of business groups (BG) and networks as e ﬃ cient organizational forms for corporate sustainability and responsibility systems (CSR), and seeing that management control systems (MCS) play a pivotal role in transmitting authority to CSR and formalizing a sustainability organizational culture, this paper aims to review the available literature in order to investigate e ﬃ cient adoptions of CSR by BGs or networks. Both organizational forms have positive e ﬀ ects on CSR development, on three levels: (a) setting industry standards (macro—external environment); (b) stimulating sustainability-oriented innovations (mezzo—member ﬁrms); (c) reputational gains, CSR expenses mitigation, and optimization of organizational capabilities (micro—individual SMEs). The studies on SMEs were useful in identifying current sustainability practices: both partial (social, environmental) and complete sustainability systems were susceptible to being integrated with management accounting, making them an almost implicit tool for proper CSR. Finally, by gathering the empirical literature on sustainability transitions of networks and groups, it was possible to trace a comprehensive introductory plan that operators could resort to for initial guidance. The six steps of this process are (1) project initiation, (2) preliminary actions, (3) change management decision, (4) ﬁrm-level activities, (5) auditing, (6) transition to territorial social responsibility (optional). goal-setting and industry sustainability benchmarking, or as a certiﬁcation-leading route towards a more “serious” change (in terms of statute and legal form of Beneﬁt Corporation). Finally, sustainability reporting was compared with integrated reporting: the latter is more of a concise managerial report (not replacing sustainability disclosure) providing detailed information on the types of capitals used for creating value (business sustainability), while the former delineates the TBL aspects of a ﬁrm, either partially or in its entirety. All the above-mentioned tools are extensively discussed in Section 4.2.2, should a more detailed explanation be useful.


Introduction
Small and medium sized enterprises (SMEs) provide a significant contribution to the development of the world economy, in terms of employment creation, innovation, and industrialization [1]. On the downside, cumulatively, SMEs are also responsible for around 60-70% of the global industrial pollution [2], which in turn negatively shapes public opinion. In order not to undermine their established relationships of trust with stakeholders and consumers alike, SMEs have been increasingly integrating corporate social responsibility, accountability and sustainability practices into their corporate strategies. Corporate social responsibility (CSR) is an important global concept that can be defined by the values it seeks to protect, such as decent working conditions and labor standards, human rights, environment protection, transparency and corruption. However, instead of using it as a passive reactive strategy, it would yield much greater results once built inside a company's core strategy, so that it can become a value creation driver [3].
However, the most successful SMEs at exploiting all the potential that CSR has to offer are those that coordinate their actions under a single economic entity. Global value chains and collaborative networks are an example of firm aggregations, exerting enormous influence on the community [3]. Networks, in fact, have already made several contributions towards the achievement of Sustainable Figure 1. The relationship between sustainability, sustainable development, corporate systems (CS), corporate social responsibility (CSR) and sustainable development goals (SDGs). Source: author's representation adapted from [12,19,[24][25][26].

Considering the Potential Impact o Small and Medium-Sized Business Groups on Sustainable Development
According to the literature, during transitional phases (e.g., internationalization, adoption of environmental practices), SMEs often lack the necessary resources, scale and benefits-awareness to access international markets. For this reason, joining a network becomes the most viable solution for them, in order to upgrade their capacity [31,32].
Networks (e.g., global value chains, industrial clusters) are an organizational form providing a stable relationship among participating companies, while maintaining their respective legal autonomy when entering into contracts with other entities on the market. BGs are a particular type of firm network, defined as a collection of legally independent companies which operate under common ownership, administrative and financial control [33] through either formal (e.g., equity) or informal (e.g., family) ties [32], often in multiple strategic and unrelated sectors [31,34].
Within the context of SME group relationships, BGs are considered a mediation mechanism. Affiliates mutually benefit from reduced transaction costs and the sharing of both risks and superior resource bundles among themselves (financial resources, human capital, advanced technologies, intangible resources such as R&D and advertising), but their allocation is not constrained and is up to each SME's individual strategy [31]. This stimulates the exchange, among affiliates, of knowledge Figure 1. The relationship between sustainability, sustainable development, corporate systems (CS), corporate social responsibility (CSR) and sustainable development goals (SDGs). Source: author's representation adapted from [12,19,[24][25][26]].

Considering the Potential Impact o Small and Medium-Sized Business Groups on Sustainable Development
According to the literature, during transitional phases (e.g., internationalization, adoption of environmental practices), SMEs often lack the necessary resources, scale and benefits-awareness to access international markets. For this reason, joining a network becomes the most viable solution for them, in order to upgrade their capacity [31,32].
Networks (e.g., global value chains, industrial clusters) are an organizational form providing a stable relationship among participating companies, while maintaining their respective legal autonomy when entering into contracts with other entities on the market. BGs are a particular type of firm network, defined as a collection of legally independent companies which operate under common ownership, administrative and financial control [33] through either formal (e.g., equity) or informal (e.g., family) ties [32], often in multiple strategic and unrelated sectors [31,34].
Within the context of SME group relationships, BGs are considered a mediation mechanism. Affiliates mutually benefit from reduced transaction costs and the sharing of both risks and superior resource bundles among themselves (financial resources, human capital, advanced technologies, intangible resources such as R&D and advertising), but their allocation is not constrained and is up to each SME's individual strategy [31]. This stimulates the exchange, among affiliates, of knowledge of Sustainability 2020, 12, 7722 5 of 42 clients, industries, and the foreign market, leading to the achievement of competitive performance levels and new opportunities in disparate industries on global markets [31,32,34,35].
BG membership additionally provides a key informational advantage, namely positive referral (or promotion effect) from sister affiliates to prospective clients and investors, concerning the reputation, trustworthiness and reliability of member SMEs. This decreases the cost and facilitates the task of matching news suppliers to their respective clients [32,34].
BG structures can also increase the environmental innovation level (development of new technology for pollution reduction or recycling) and labor productivity of its SMEs, by suitably allocating labor resources within the group and providing an internal learning network to its member firms, for exchanging innovative ideas, technologies and know-how [32].
Moreover, enterprises forming BGs significantly improve their accounting and stock market values. In particular, when institutions fail to support labor, production and financial capital, which results in high transition costs, BG configurations are able to internalize labor, capital and product markets, thus partially offsetting these institutional voids [35].
All in all, due to their adaptive nature and remarkable effectiveness on marketplace variables, BGs are capable of stimulating a country's economic and social development, even under weak institutional contexts [31,32]. The Indian Tata Group, for instance, launched their mini truck with the aim of overcoming the challenge of driving on poorly constructed roads [36]. Groups of SMEs would normally produce an even greater effect, due to their flexible structures, quick decision-making processes and unique know-how in specific areas [37]. There are numerous examples of SME groups getting awarded with a grant for their highly innovative and impactful R&D projects (Fibertech Group, Proxigroup, InnovativeHealth Group, etc.) [38]. All this considered, along with the fact that SMEs have been increasingly focusing on environmental and other CSR activities to meet their stakeholders' needs and gain a further competitive advantage [32], it is easy to come to the conclusion that groups of SMEs could potentially provide an even greater impact on sustainability.
The above points can be grouped into three types of advantages each organizational configuration provides to the other, within the context of small and medium-sized groups (Table 1): structural, informational, focus on sustainability. Table 1. Mutual advantages provided by business groups (BGs) and small and medium-sized enterprises (SMEs) in small and medium-sized groups: (1) structural, (2) informational, (3) sustainability.

BG's Advantages for SMEs
SMEs Advantages for BGs

Sustainability
• Enhanced environmental innovation level through effective allocation of labor productivity • Increased focus on gaining a competitive advantage through CSR

Management Control Systems for Sustainability
Contributions to SD at micro-levels can only be efficient when enterprises start making tangible efforts towards sustainability. Commonly, only partial aspects of SD are addressed at organizational level, with environmental responsibility and innovation being the most chosen route, while social actions are often disregarded [22].
Environmental innovation strategies alone, however, are not a guarantee for the achievement of successful financial and sustainability outcomes [39]. In this sense, research suggests that only if enterprises align their sustainability and innovation strategies with internal controls, will they be able to gain performance improvements and make noticeable progress towards SD [22,39].
From a theoretical point of view, internal controls, or MCS, are a set of formal and informal practices that are used to manage patterns in organizational activities, building upon an organization's information system (e.g., data queries, computations, functions, modeling, reporting). Formal controls include planning and goal-setting, budgeting, market share and outcome monitoring, and behavior controls through explicit measures and written rules (e.g., performance appraisal, reward criteria, code of ethics) [40][41][42][43]. Conversely, informal controls consist of traditions, attitudes, knowledge, beliefs and shared values that moderate individual behaviors within a firm, thus shaping corporate culture [40,42,44].
MCSs support the effective implementation of corporate strategy (competitive positioning), strengthen transparency and accountability towards stakeholders, ethical decision-making and management of environmental opportunities and threats [39]. MCSs are based on four different formal levers that operate in tandem, called levers of control (LOC): (i) belief (core values), (ii) boundary (risks to avoid), (iii) diagnostic (critical performance variables), and (iv) interactive control systems (strategic uncertainties). Belief and interactive controls are enabling forces (motivational), while the other two constructs are used for controlling purposes (ensuring compliance) [43]. In particular, enabling levers of MCS foster a positive impact of environmental innovation strategy on sustainability performance, whereas controlling MCS levers negatively mediate this relation [39].
Each of the above levers can help managers to reinforce their company's CSR ( Figure 2). Through belief systems, firms are able to mobilize their employees' ideas (through mission statements, workshops, training sessions, etc.) in order to strengthen CSR values, while increasing their commitment to a shared vision.

Methodology
The systematic literature review was developed in four stages: (i) choice of keywords and inclusion criteria, (ii) search strategy, (iii) study screening and selection, (iv) extraction and synthesis of sources. Each step is described in detail below. Boundary systems draw on a set of tools directed towards internal and external stakeholders (employees, supply chain, customers, environment, communities), including codes of ethics and conduct, guidelines, quality certifications and labeling standards. These measures are used to stimulate innovation thinking, set criteria for supplier selection, ensure product and process quality and compliance with sustainability norms, as well as prevent environmental, socio-economic and internal risks.
Firms make use of diagnostic systems to develop measurable outcomes for their CSR practices and assess their cost-effectiveness and value creation, as well as any deviations from strategic targets. Through these systems, companies are able to internalize the relative net benefits and enable CSR decision-making on the one hand, and communicate performance results to stakeholders on the other. Internally, social indicators and reports should be used to provide feedback to human resources, however, research found that not many companies adopt a social diagnostic system [45].
Interactive control systems allow companies to leverage both primary and secondary stakeholders' (non-governmental organizations, activists, communities and suppliers) opinions in order to gain insight into additional CSR and sustainability policies, and therefore identify further opportunities and threats (that might undermine the organizational image) carrying an impact on CSR.
Informal controls are used to sustain the above-mentioned formal processes. Their purpose is to project the organizational climate onto an enterprise's internal and external stakeholders, so that they gain awareness of how it helps to strengthen CSR culture and commitment [7,22,45].
In spite of the key role played by formal controls in signaling a company's consideration of its stakeholders and responsibility goals, they are not capable of emphasizing sustainability in relation to their internal culture on their own. In other words, informal systems alone would lead to unstable CSR management [46]. According to research, formal and informal controls are actually mutually reinforcing and their combination can prevent any perplexities or opportunistic behavior and positively stimulate the members of a firm to implement higher-level CSR [7,22,45].
After understanding the essential components of an MCS for sustainability, the next step would be to analyze which types are currently in use.
Conventional, or 'cybernetic', MCS techniques (e.g., cost accounting, budgeting), are deemed to be limited to the attainment of economic objectives. As they do not yield any significant improvement in the social and environmental spheres, companies started looking for other solutions in the last decade [22,39,47]. More contemporary management accounting techniques, such as benchmarking and balanced scorecard (BSC), seem to have a slightly better influence, not only on sustainability, but also on innovation and international presence as well [39].
BSCs, in particular, are quite useful in delivering the discipline that can formally make TBL objectives operational and measurable for sustainability disclosure [44,48]. This is important because the non-conventional data provided by TBL reports cannot rely upon official standards for reference, unlike mainstream MCS reporting [46]. BCSs benefit, in turn, from the integration with the TBL, as it improves their interaction with external stakeholders [49]. The sustainability balanced scorecard (SBSC) is a successful example of the integration between formal tools and sustainability strategies [44]. Integrated tools undergo a more meaningful transformation and serve SD implementation better.
Nonetheless, in order to suitably address the social and environmental issues raised by various stakeholders, and at the same time support the transition towards sustainability, traditional management control has been gradually revised and more specific concepts began surfacing in the literature [22,39,47]. Umbrella terms, such as environmental management accounting (EMA), social accounting, sustainability accounting, and social and environmental accountability, are the most frequent examples [46].
In terms of environmental controls, EMA was found to be positively related to process innovation, but did not appear to have a positive impact on product innovation [39]. Social controls capture both informal and formal procedures concerned with human resource management, but also the tacit knowledge owned and applied by the individuals in the firm to their everyday work.
Sustainability controls are the most comprehensive type of system, in that they encompass both environmental and social strategies, in addition to traditional economic objectives, extending the scope of MCSs and promoting organizational learning and change. Similarly to MCSs, Sustainability Control Systems (SCS) are a link between strategy and operations [47,48,50].
Researchers found two main barriers to the consolidation of sustainability aims into corporate strategy. First, when SCSs are applied as a diagnostic system in place of an interactive one, managers risk ignoring sustainability uncertainties. Second, companies might fail to connect MCS and SCS into a unified system, since the integration should simultaneously occur on a (i) technical (sustainability and financial data reporting), (ii) organizational (shared responsibilities and skills between management accountants and sustainability managers, not limited to a group of specialists), and (iii) cognitive level (shared understanding and perspective between financial and sustainability managers). Nevertheless, a technical integration alone might partially compensate for the insufficient integration of the remaining two dimensions [47]. In general, the successful design of sustainability policies within an organization is only possible when traditional control systems are extended through SCSs [48]. It is also a matter of consistency, because when an organization's MCS fails to accept and externalize its claim to operate in a socially responsible manner, it may lose credibility in the eyes of its stakeholders [46].
To sum up, MCSs play a pivotal role in supporting the operationalization of sustainability objectives, as well as in improving CSR communication and formalizing a sustainability organizational culture.

Methodology
The systematic literature review was developed in four stages: (i) choice of keywords and inclusion criteria, (ii) search strategy, (iii) study screening and selection, (iv) extraction and synthesis of sources. Each step is described in detail below.

Choice of Keywords and Selection Criteria
Keywords for the literature search were chosen based on the main research question: 'How can SMEs in cooperative relationships leverage on sustainability-integrated MCS tools to effectively implement CSR?' (Figure 3). This question was divided into three main topics, namely (a) type of relationship, (b) sustainability concepts for companies, and (c) internal control systems. For each of the three conceptual categories, a series of associated terms were picked for the next step: (a) Business/corporate/manufacturing group, group of companies, intercompany, intragroup, SME network; (b) Sustainability, sustainable management, sustainable development (goals), responsibility ethics, corporate social responsibility, corporate social performance, corporate sustainability, environmental social governance performance (ESG); (c) Management control (system), management/managerial accounting, cost accounting/management, strategic control, corporate governance, board of directors.
Subsequently, the following criteria were determined in order to select the articles for review: (1) only articles in English, excluding grey literature (e.g., conference proceedings); (2) inclusion of environmental, social and economic corporate sustainability, not economic sustainability alone; (3) only studies combining both group and/or SME organizational forms with corporate sustainable practices were included; (4) SME literature was deemed eligible only if it examined networks, sustainability-oriented innovations or social/environmental accounting; (5) focus on the corporate-level SD, not on a specific country's SD (country-specific BG examples are, however, included, e.g., Korean chaebols); (6) business cases are considered only if discussed in scientific articles, no short news reporting/cover stories; (7) results restricted to the for-profit sector, no third-sector organizations Sustainability 2020, 12, 7722 9 of 42 (e.g., cooperatives); (8) mainly the manufacturing industry is taken into account, no services; (9) not restricted to sustainability in the production process, rather, including studies on sustainability as a strategic asset for corporate governance. Subsequently, the following criteria were determined in order to select the articles for review: (1) only articles in English, excluding grey literature (e.g., conference proceedings); (2) inclusion of environmental, social and economic corporate sustainability, not economic sustainability alone; (3) only studies combining both group and/or SME organizational forms with corporate sustainable practices were included; (4) SME literature was deemed eligible only if it examined networks, sustainability-oriented innovations or social/environmental accounting; (5) focus on the corporatelevel SD, not on a specific country's SD (country-specific BG examples are, however, included, e.g., Korean chaebols); (6) business cases are considered only if discussed in scientific articles, no short news reporting/cover stories; (7) results restricted to the for-profit sector, no third-sector organizations (e.g., cooperatives); (8) mainly the manufacturing industry is taken into account, no services; (9) not restricted to sustainability in the production process, rather, including studies on sustainability as a strategic asset for corporate governance.

Search Strategy
A structured keyword search (selected period 2007-2020, based on the comprehensive availability of articles on the topic) was performed in three major electronic databases (EBSCO, Wiley, Web of Science) covering a broad range of high impact factor journals, as well as the Sustainability Journal separately, and through the search engine. Sources were identified by using various string combinations of the three keyword groups (I: a-b-c; II: a-b; III: b-c) and applying the abovementioned inclusion criteria.

Study Screening and Selection
In order to ensure the maximum relevance to the aim of the present review, three levels of screening were carried out, in addition to a pre-screening of the chosen databases, after which a total of 836 records were identified. The flow chart below ( Figure 4) shows the study selection process.

Search Strategy
A structured keyword search (selected period 2007-2020, based on the comprehensive availability of articles on the topic) was performed in three major electronic databases (EBSCO, Wiley, Web of Science) covering a broad range of high impact factor journals, as well as the Sustainability Journal separately, and through the search engine. Sources were identified by using various string combinations of the three keyword groups (I: a-b-c; II: a-b; III: b-c) and applying the above-mentioned inclusion criteria.

Study Screening and Selection
In order to ensure the maximum relevance to the aim of the present review, three levels of screening were carried out, in addition to a pre-screening of the chosen databases, after which a total of 836 records were identified. The flow chart below ( Figure 4) shows the study selection process.
A total of 114 items remained based on an initial screening of titles, abstracts and keywords, and considering some of the inclusion criteria (mainly 7,8,9). Additionally, some of the duplications found at first glance were also removed at this stage. The second level screening resulted in 102 articles being kept for further analysis (minus 12 duplicates). The third step involved a more thorough inspection of abstracts and available full-texts. Papers were reconsidered through the complete set of inclusion criteria. Specifically, 13 results were removed according to the 1st criterion (five other languages and eight proceedings), one result was removed considering the 2nd criterion, and 43 items were ignored based on context appropriateness and the remaining criteria (3,4,5,6). At this point, three relevant sources were also added from search engine results. This process resulted in 48 remaining articles (33 of the texts were further discussed in a content analysis), for the remainder of which full texts were retrieved. Sustainability 2020, 12, x FOR PEER REVIEW 10 of 44 A total of 114 items remained based on an initial screening of titles, abstracts and keywords, and considering some of the inclusion criteria (mainly 7,8,9). Additionally, some of the duplications found at first glance were also removed at this stage. The second level screening resulted in 102 articles being kept for further analysis (minus 12 duplicates). The third step involved a more thorough inspection of abstracts and available full-texts. Papers were reconsidered through the complete set of inclusion criteria. Specifically, 13 results were removed according to the 1st criterion (five other languages and eight proceedings), one result was removed considering the 2nd criterion, and 43 items were ignored based on context appropriateness and the remaining criteria (3,4,5,6). At this point, three relevant sources were also added from search engine results. This process resulted in 48 remaining articles (33 of the texts were further discussed in a content analysis), for the remainder of which full texts were retrieved. Table 2 shows the results after each stage. It is worth noting that the keyword string combinations of group I (a-b-c) did not produce many results (n = 52). This shows that the integration of MCSs and CSR is scarcely studied in the literature, and in particular with respect to companies affiliated through BG relationships or part of a network. Conversely, the most researched topic combination is BG/SME and sustainability (n = 696).  Table 2 shows the results after each stage. It is worth noting that the keyword string combinations of group I (a-b-c) did not produce many results (n = 52). This shows that the integration of MCSs and CSR is scarcely studied in the literature, and in particular with respect to companies affiliated through BG relationships or part of a network. Conversely, the most researched topic combination is BG/SME and sustainability (n = 696). The bottom right corner shows the resulting items after each screening phase.

Extraction and Synthesis of Sources
The full texts of the selected articles were analyzed in depth. Pertinent information was then broken down into comparable data and organized through a spreadsheet. Table A1 (in the Appendix A) below summarizes the following details for each included study (the ones whose key findings will be examined thereafter are highlighted): focus on BG or SME, authors and year of publication, journal, country of research, scope of research (e.g., country, project), research type (conceptual, empirical quantitative/qualitative) and method used (e.g., experiment, case analysis), topics, limitations (with respect to the present review). Topics were further grouped into three categories, relating to sustainability (S.), corporate governance or MCS or accounting (M.), and SD-MAC combined (SM.). In order to ensure validity (by widening the variety of sources) [51,52], the collection of articles was based on a triangulation of topics [53][54][55] (organizational forms of BG, network and SME) and methods applied (conceptual research, empirical qualitative research, empirical quantitative research with either analysis of reviews, business cases and experiments). Reliability and trustworthiness could be achieved by following rigorous and systematic steps, including a thorough four-tier literature screening and the application of pre-defined selection criteria for the retrieval of papers, making their content consistent with the aim of this review as closely as possible [52,56]. Additionally, we assessed the heterogeneity of sources to understand if a meta-analysis on the correlation between CSR and BGs was possible. However, only five studies were eligible, and we therefore decided not to proceed, as such a small number would not have been able to accurately predict the overall correlation. Subsequently, further quantitative techniques (e.g., sensitivity and subgroup analyses, meta-regression) were also excluded for the same reasons. Overall, given the thematic interest of the research question, the current review can be more accurately classified as a qualitative systematic review [57,58], thus focusing more on a conceptual analysis of the literature.

Descriptive Analysis: Literature Trends
The present section provides some numerical insights into the 48 studies included in the review. To begin with, the articles retrieved were published in the period 2007-2020 ( Figure 5), with a peak in publications in 2018.
Splitting the time span under observation into three clusters of uniform cumulative periods, it is possible to notice that there has been a constantly growing trend in publications on corporate sustainability management in SMEs and BGs. Specifically, while the increase in SME studies has been less than proportional, research on practices in BGs has outweighed that on SMEs since 2014-2017 (first appearing in 2010). Nevertheless, considering the entire sample, the interest in either SMEs or BGs was balanced (n = 21 each), likewise for emerging (n = 22) and developed economies (23). Papers specifically analyzing sustainability in BGs of SMEs were extremely rare (n = 6), and, cumulatively, it seems that interest in them has gradually decreased.
Concerning geographical scope, developed markets have been quite a stable focus over the three considered periods, while interest in emerging markets has cumulatively rapidly grown from 2013 onwards.
With regards to types of study, conceptual works such as literature reviews remained low over time. In empirical studies, quantitative approaches seemed to slightly prevail over qualitative ones, especially during the period 2017-2019. Experiments and case analyses were the most chosen designs for quantitative empirical research (survey, in most cases, were used to collect data for experiments). Nevertheless, while case studies were almost constantly used throughout the period in question, hypothesis testing only began taking place in 2013. Once again, in 2018, they were subjected to a rapid increase. especially during the period 2017-2019. Experiments and case analyses were the most chosen designs for quantitative empirical research (survey, in most cases, were used to collect data for experiments). Nevertheless, while case studies were almost constantly used throughout the period in question, hypothesis testing only began taking place in 2013. Once again, in 2018, they were subjected to a rapid increase.  Table 3 provides an overview of the frequency of journals that published about sustainability in BGs and SMEs. As expected, publications that are normally concerned with sustainability and ethics engaged in the topic the most. These also appeared to discuss specific tools for sustainability recurrently: integrated measures (social and environmental) were the most common, followed by environmental measures and, to a lesser extent, contemporary MCS tools, such as benchmarking, also in its adapted version for sustainability. Among the most popular journals in the sustainability and ethics category were the Journal of Business Ethics (n = 6), Journal of Cleaner Production (n = 5), Corporate  Table 3 provides an overview of the frequency of journals that published about sustainability in BGs and SMEs. As expected, publications that are normally concerned with sustainability and ethics engaged in the topic the most. These also appeared to discuss specific tools for sustainability recurrently: integrated measures (social and environmental) were the most common, followed by environmental measures and, to a lesser extent, contemporary MCS tools, such as benchmarking, also in its adapted version for sustainability. Among the most popular journals in the sustainability and ethics category were the Journal of Business Ethics (n = 6), Journal of Cleaner Production (n = 5), Corporate Social Responsibility & Environmental Management (n = 3), and Sustainability (n = 3). Among the accounting and management journals, the Journal of Small Business Management was the only one touching on all five types of tool in one paper. Abbreviations: EM = environmental management; Int = integrated systems; SoM = social management; SuMC = management control system adapted for sustainability; TCMC = Traditional and contemporary management control system. Journals in grey featured specific MCS-CSR tools, journals in red are sustainability-specific and present MCS-CSR different tools.
In the articles that did at least mention some sustainability management tools, the main focus was on integrated (37%) and environmental (34%) approaches, and mainly SMA (7%) and EMS (12%) respectively (Figure 6a,b). Social management (e.g., SIA) and MCS-sustainability-adapted tools (e.g., sustainability BSC) were less used, while in MCSs, contemporary tools such as benchmarking/BSC (5%), were predominantly deemed suitable for sustainability management (Figure 6a,b). Researchers were mainly interested in reviewing previously written papers (24%) when studying sustainability management tools, and in this case all categories were analyzed ( Figure 6c). Studies concentrating on the Italian situation were the second most frequent (22%), then came those exploring Lithuanian context (18%). Environmental management and integrated tools prevail in both geographical focuses, with the only difference being that social management is additionally taken into consideration for Italy. The countries evaluated in terms of sustainability management tools are all developed economies, except for Colombia and India.
the Italian situation were the second most frequent (22%), then came those exploring Lithuanian context (18%). Environmental management and integrated tools prevail in both geographical focuses, with the only difference being that social management is additionally taken into consideration for Italy. The countries evaluated in terms of sustainability management tools are all developed economies, except for Colombia and India. The most active researchers on the topic of sustainability in BGs and SMEs were located in Italy (14%), South Korea (13%), and the USA (11%). However, while South Korea and the USA were mostly interested in finding out about business groups, Italian studies were mainly focused on SMEs and, to some extent, SMEs in BGs. Empirical approaches were chosen by all researching countries, except for The most active researchers on the topic of sustainability in BGs and SMEs were located in Italy (14%), South Korea (13%), and the USA (11%). However, while South Korea and the USA were mostly interested in finding out about business groups, Italian studies were mainly focused on SMEs and, to some extent, SMEs in BGs. Empirical approaches were chosen by all researching countries, except for Norway. Conversely, the majority of conceptual articles were written in larger economies, with the exception of Thailand and Turkey (Figure 7a).
Italy and South Korea (both 14%) were also primarily chosen as countries of investigation (they often study their own internal situation), but not the USA (2%). In its place, India (14%) and Spain (10%) gathered major attention (Figure 7b). Studies on Indian BGs were quite popular, while Spanish circumstances were similar to Italy (focus on SMEs and partly on BGs of SMEs). In summary, South Korea and India (APAC) are the most researched emerging markets, focusing primarily on country data in terms of research scope (Figure 7c), while Italy and Spain are the most studied developed economies (EMEA).
(10%) gathered major attention (Figure 7b). Studies on Indian BGs were quite popular, while Spanish circumstances were similar to Italy (focus on SMEs and partly on BGs of SMEs). In summary, South Korea and India (APAC) are the most researched emerging markets, focusing primarily on country data in terms of research scope (Figure 7c), while Italy and Spain are the most studied developed economies (EMEA).

Content Analysis
This section analyzes the content of 33 of the selected papers, covering three major topics: (1) correlation between firm aggregations, like affiliations or networks, and CSR success; (2) overview of sustainability management tools used by SMEs; (3) corporate sustainability processes developed in SME networks/groups.

The Influence of Group Affiliation and Networks on the Intensity of CSR Implementation
The literature on the relation between BG affiliation and CSR intensity features mixed evidence, the majority of which, however, is positive. Compared to stand-alone firms, group affiliation normally resulted in better CSR performance overall, including environmental, social and governance ratings (ESG-a proxy for CSR but based on more precise criteria for assessment), and for its individual social and environmental components [5,6,[59][60][61]. The social score seems to yield an even stronger effect in larger groups and for such dimensions as employment, human rights, community and product responsibility, but less in terms of safety, training and diversity. Concerning the environmental aspect, remission and resource reduction, as well as product innovation/R&D are the factors responsible for raising CSR intensity in BGs [59,60].
Conversely, other studies suggested that publicly listed groups in particular do not aggressively invest in CSR activities [62], and that the higher cost of equity for disclosing nonfinancial information, makes CSR reporting less valuable to BGs [63].
As for the positive BG-CSR correlation, this depends on the intrinsic characteristics of BGs themselves. First of all, size (several companies in one group) and years of experience significantly affect corporate sustainability. Specifically, larger and older BGs have a higher availability of resources, therefore it is easier for them to invest in CSR [59,64].
Second, the support provided by BG promoters (families or controlling corporations) is equally important. Unlike the promoters of unaffiliated firms (individuals), which are exclusively interested in profits, promoters of BGs are genetically interlinked with society, and thus feel compelled to also nurture socio-economic wealth [61]. Family control, counter to the belief that it is only a source of opportunistic expropriation of CSR investments, proved to be an excellent leverage for increasing a BG's environmental disclosure propensity, mainly if leadership is taken by a family CEO [64]. Some authors, however, state that it is group affiliation itself that mitigates the negative effects of family ownership on CSR, and this is only true for non-individual family owners [5]. As for controlling companies, they exert significant influence on subsidiaries, both if these operate in their parent company's sector, or in a different industry but with notable direction and coordination by the holding. This leads affiliated firms to adopt their same sustainability practices and improves their individual corporate social disclosure, demonstrating that a BG is indeed a united economic entity, even when it comes to sustainability performance [65]. Peer pressure by likewise affiliated firms plays an influential role too. As a matter of fact, if some affiliates already have previously disclosed environmental information, the disclosure propensity among the other group members increases [64]. The external BG influence dynamic is also to be noted. When it comes to the promotion of socio-economic wealth, BGs can truly make a difference, as they wield considerable political power in shaping the local legal framework for their respective societal contexts, thanks to collaborations with governments [66]. Their sustainable business operations often inspire other BGs to transition towards CS too [6].
BGs do not primarily resort to CSR-related tools to address narrowly defined environmental issues; they instead rely on its insurance-like effect to obtain reputational gains [59,64]. Sustaining or restoring group reputation is particularly important during negative group-specific externalities (e.g., dissemination of bad news among member firms) [59], as well as when members need to be protected from inherent reputational risks emerging from embezzlement schemes potentially put in place by family owners [64]. A good reputation particularly helps BGs to convince international stakeholders during the internationalization process, when they have a tendency to communicate more CSR activities [67]. The one case mentioned in which BGs do not need to worry about recognition is when they hold the dual status of state-owned BG. These organizations are in fact naturally afforded both legitimacy and protection from negative CSR performance, making them less compelled to conduct sustainability-related activities to maintain their reputation [68].
Seeing that groups are composite entities, it is also interesting to understand how the adoption of CSR within a BG influences each member firm. Researchers have distinguished between the benefits and costs of affiliation for CSR-deploying SMEs. On the benefit side, coordination of all group-level sustainability activities by centralized headquarters makes it possible to efficiently allocate all internally available resources (information advantage). The fact that all group members are linked to one another allows the headquarters to generate spillovers of accumulated expertise, reputation capital, and group-level donations (a good proxy for social investments), improving CSR performance homogeneously across the BG [5]. Particularly, SMEs that are part of a BG benefit in terms of improved environmental innovation, thanks to the moderating effect of complementary assets and the sharing of external investments and risks. Higher levels of environmental innovation, in turn, indirectly improve labor productivity (through closer employee involvement in sustainability), making it possible for group-affiliated SMEs to fulfil environmental regulations, at times even exceeding mandatory requirements, but also productivity requirements moved by shareholders [6,32]. Finally, BGs mitigate the negative relationship between CSR and financial performance, but only at low CSR levels [60]. Nonetheless, this attenuated effect between CSR and earnings management (considered a reliable metric in the absence of a standard framework for CSR) is at times suggestive of a managerial opportunistic behavior that uses CSR to conceal poor earnings quality [69]. This means that, in some cases, group affiliation actually weakens the ability of unexpected accounting earnings to reflect the potential benefits of CSR spending [70]. In general, however, the intensity of sustainability activities is positively related to reputation, which in turn allows firms to decrease company total costs in the long term. This happens because consumers are more supportive of socially responsible companies, and therefore more willing to accept the premium pricing, allowing firms to generate value [71].
On the cost side of BG affiliation, resource-rich members are requested to contribute more to the group resource endowment, subsequently having to abandon certain investment opportunities in order to support poorly performing affiliates with their CSR [6].
Network models have also been assessed in the literature as aggregated forms of SMEs involved in CSR-related activities (especially environmental management). The cluster approach, for example, was found to be useful in accelerating the uptake of CSR on three levels. From the macro perspective (network to external environment), it helps to develop a unitary brand identity which increases negotiating power internationally (investors' confidence) and support to policy makers in setting environmental and social priorities/standards for the local industrial system. According to the mezo perspective (network members interactions), clusters provide a common long-term strategic direction, as well as knowledge shared from different businesses (supporting capacity building for members). This fosters a multiplier effect on all partner organizations in terms of involvement and intra-network synergies, promotes corporate learning, and enables common management, certification and audit systems. Besides, clusters act as innovation drivers and stimulate continuous competitiveness through peer encouragement, helping to differentiate the cluster as a whole from its direct rivals.
On a micro-level, clusters help each individual SMEs to minimize any operational barrier (lack of financial, expertise and time resources), while at the same time legitimizing pro-active engagement in all CSR activities, as organizations increase their ethical awareness to act on sustainability issues. In this sense, organization capabilities (e.g., staff/management specialization, finances, knowledge building) are optimized, technical complexities and costs associated with CSR implementation are reduced, and due diligence and vigilance are increasingly implemented [3,72,73].
When approaching sustainability-oriented innovations (SOI), and more specifically organizational environmental innovations (e.g., EMS), as part of an innovation-based or sustainability strategy, SMEs tend to be more prone to spanning their boundaries through existing knowledge networks with key actors for innovation (e.g., technical centers, research institutions, universities). In this context, three different learning-action patterns can be observed. If the SME concentrates on resource acquisition (grazer network pattern), learning for SOI is limited to being exploitative (new knowledge applied commercially), because missing firm resources are simply complemented to realize pre-determined innovation opportunities. The second type, explorer behavior, focuses on the acquisition of new ideas and information per se, supporting the broadening of prior network experiences and the translation of the acquired knowledge into firm processes. Finally, if a firm already has extensive prior experience with networks and is sustainability-rooted, it will then pursue the networker pattern, which allows it to expand its interaction ties externally for support and benchmarking, and enjoy a gradual learning process to strengthen innovative capacity for SOI (both exploitative and exploratory learning are feasible) [73,74].

Systems and Tools for Sustainability Management in SMEs
After having discussed the relationship between composite organizations and CSR, a more in-depth focus on sustainability practices adopted by the individual organizations that are part of groups and networks is necessary. SMEs can benefit from the implementation of a CSR strategy in many ways. It helps them gain better access to talent, improve their employer-employee and supplier-buyer relationships, increase brand equity (or publicity, which fosters investors' interest in forming joint-ventures), save on costs in the long-run (through lower energy consumption and employee turnover), and develop a differentiation strategy. CSR can also minimize certain SME-specific risks, such as restricted market access (strategic risk) due to not having a specific sustainability certifications or systems required by some foreign buyers [3]. However, in order for SMEs to develop, monitor, and actually benefit from organizational sustainability practices, in terms of performance and innovation, CSR should be integrated into MCSs. Technically, this will allow the transmission of rigorous planning, reporting and monitoring mechanisms from MCSs to CSR [75], while, socially speaking, formal interactive controls will help CEOs motivate employees and translate stakeholders' opinions into sustainability actions, through interaction with the company's CSR policy [7].
Different levels of integration between MCSs and CSR were identified through the review. Traditional (cost accounting, budgeting) and contemporary control types (benchmarking and BSCs) are both used in the absence of a specific sustainability system within the organization. Nonetheless, contemporary MCSs have a stronger moderating effect on sustainable innovations for international performance [75]. The BSC, for instance, has been found to be quite suitable for addressing the limit that SMEs have in focusing exclusively on financial and operational performance. BSCs in fact supplement traditional financial measures (F) with three additional perspectives, namely delivering value to customers (C), promoting the efficiency and effectiveness of internal business processes (P), and learning and growth (L) for acquiring capabilities to face future challenges [75,76]. For slightly more advanced and complex system needs, this tool can also be reconfigured to include sustainability. This can be achieved by adding a fifth perspective, developing a sustainability BSC from scratch, or integrating various indicators throughout the original four perspectives. The latter case includes an initial selection of sustainability key performance indicators (KPI), performance ratings and relative importance weights of indicators using the fuzzy analytic hierarchy process (FAHP). The obtained weighted performance ratings are subsequently filtered through a three-stage hierarchal fuzzy inference system (FIS) on all four perspectives in order to obtain the final sustainability score. The FAHP and FIS methods are especially useful in dealing with the subjectivity and vagueness of manufacturing decision-making, translating opinions in linguistic terms into reliable crisp values. An empirical study applied this framework and identified that the most important indicators for sustainability performance are manufacturing cost and debt ratio (F), customer satisfaction and quality (C), material intensity and hazardous material ratio (P), annual training hours per employee and management commitment (L) [76]. Performance measurement systems (PMS) are the broader processes that embed BSCs and other tools. Similar to BSCs, PMSs can be converted into sustainability-focused tools by incorporating the relevant indicators. This way, they will assist management in defining sustainability objectives, developing socio-economic and environmental activities, identifying critical areas, as well as efficiently distributing scarce resources [77].
Traditional cost accounting (measuring deviations between actual production costs and strategic objectives) [75] was adapted in a much more structured way into a stand-alone sustainability MCS tool. The material flow cost accounting (MFCA), also known as ISO 14051, is a recognized international standard that helps organizations both achieve economic goals and optimize material use, without prioritizing only cost saving or waste reduction. It physically traces material flows, detailing quantities and costs. Material losses are thus readily visible, making it easy to identify inefficient processes. MFCA can be regarded as a managerial innovation technology and an efficiency tool for SMEs to be flexibly applied to processes, products, an entire plant, the whole company, or even the supply chain [78].
Under different circumstances, firms may choose to invest into a separate CSR system, and then incorporate MCS elements into it. If SMEs decide to manage the social aspects alone, then social management systems or social impact assessments (SIA) are typical partial models to look out for. SIA aims to identify, evaluate, and minimize negative social outcomes, while maximizing its targeted social mission [77,79]. Social accounting and auditing (SAA), as well as social return on investment (SROI), are the most established SIA methods among many. SROI, in particular, is able to compare different types of benefit values and measure outcomes rather than just tracking output [80]. In order to demonstrate social responsibility towards workers specifically, the Occupational Health and Safety Assessment Series (OHSAS) 18,001 and Social Accountability, on workers' rights and workplace safety (SA8000) certification standards can be adopted.
The other side of the coin is environmental measurement and, compared to the previously examined systems, a much wider variety of strategies and implementations are found in the extant literature. On the strategic side, the managerial philosophy of eco-efficiency encourages SMEs to become more environmentally responsible, while pursuing parallel economic savings [81]. Not all SMEs, however, are capable of carrying out good practices, since, according to a study in an emerging market, around 60% of respondents were not even aware of SD issues. The development of appropriate training schemes towards an internal sustainability culture [82], along with the application of strategic and financial controls to eco-efficiency (broadly known as eco-control) [83], may solve this. The following tools for eco-efficiency were identified in SMEs: environmental management system (EMS), eco-mapping, and environmental performance measurement (EPM).
EMSs are based on scrupulous and recurrent cycles of planning, implementation and reviewing (organizational environmental control), ensuring interaction among the principal organizational functions on environmental operations, impacts and operative efficiency. They are commonly audited, which makes them useful for addressing regulatory demands [82,84]. The most prevalent EMSs are the ISO 14001 standard and the eco-management and audit scheme (EMAS). The first is directed towards organizational improvements (efficiency, effectiveness of internal processes) and, indirectly, at performance output. The second concentrates directly on performance outcomes, credibility and transparency, and supports public accountability through mandatory reporting [84]. It can be applied both for environmental certification purposes but also for any other eco-project not requiring formal accreditation [73].
Both systems are mostly popular in Europe and rely on the maturing of internal control systems and accounting practices. The major advantage of such standardized systems for SMEs is that they represent an assurance mechanism for stakeholders or against regulatory pressures, providing firms with the ability to demonstrate commitment through formalized environmental management. Networks seemingly maximize EMS's effects in SMEs, as they decrease the uncertainty from working with similar businesses, trade associations or environmental bodies (experiences and costs are shared) [84].
It is worth mentioning that total quality management (TQM) is also considered an EMS by some authors [82]. TQMs are also quite similar to quality management systems (QMS or ISO 9001), with the exception that QMSs are standardized and audited, similarly to EMS-ISO 14001. ISO 9001 and ISO 14001 can be used complementarily (similar Plan-Do-Check-Act structures, but clauses do not directly align), with QMS providing a systematic approach for maintaining consistent quality internally, and ISO 14001 being used for measuring and improving environmental impact [85].
The implementation of either ISO 14001 or EMAS can be achieved using eco-mapping, a step-by-step process to integrate environmental actions into an SME's daily activities [86,87]. This is a do-it-yourself, visual toolbox for conducting on-site environmental reviews and internal audits. It allows firms to prioritize problems, increase employee participation and training through a participatory learning processes, improve communication, and form the basis of environmental documentation [87].
Outcomes resulting from environmental management have to be evaluated in order to prompt improvement. In this regard, EPM can be seen as the penultimate stage of an EMS or its logical continuation. One of the measurement tools developed to systematically integrate environmental performance into SME decision-making processes is the EPM-KOMPAS. Its most salient feature is the capacity to recognize a firm's strengths and weaknesses, as well as the associated environmental opportunities and threats, at an early stage [88].
At the basis of environmental performance measurement, and ultimately environmental management, is the identification, collection, evaluation, distribution and control of data. These activities are essential for SMEs to be able to truly transition to CS, however, a good 70% of firms still had issues establishing environmental indicators [82]. In this review, we identify three synonymous terms that describe the above processes: environmental management accounting (EMA), environmental and sustainability accounting (ESA), monitoring and environmental control (MEC). EMAs, similarly to MCSs, and support management in the accurate gathering of necessary data for internal decision-making, and they can either be the result of integrated existing accounting systems or environment-related accounting systems built from scratch. They collect two types of data: physical (flows and uses of material, energy, water and waste) and monetary (environment-related earnings, savings, and such costs as emission/waste treatment, material purchase value of non-product output and inefficient production-materials turned into emissions/waste). The data analysis techniques typically used in EMAs are benefit assessment, full-cost accounting, life-cycle costing and strategic planning for environmental management [89,90].
In terms of reporting, several international bodies offered structured guidelines for self-disclosure on environmental information, among which the Climate Disclosure Standards Board (CDSB) framework and the Greenhouse Gas accounting standards (GHG Protocol) are worth mentioning [91]. Since companies, at times, focus too much on either compliance or stakeholder engagement, it is advisable for them to decouple environmental accounting information from environmental communication to stakeholders, so as not to lose track of their CSR strategy [92].
Apart from separate social or environmental management, firms also have the option to directly choose a sustainability performance system encompassing both aspects. Numerous integrated tools were identified for SME use. The ISO 26000 international standard is a (not certified) consolidated framework providing guidance on how to operationally articulate social responsibility into achievable micro practices [77,91].
Sustainability management systems (SMS) equally provide guidelines and are oriented towards handling sustainability as a package, helping to set strategic goals, design support tools and measures, and establish strategic action plans [93]. The last step of the SMS roadmap, namely performance analysis, can also be taken over by a stand-alone sustainability performance management systems (SPMS). It is considered an excellent method for capturing the complexity of the TBL, as it identifies and measures progress towards all drivers (economic, social, environmental) [77].
One of the studies reviewed additionally introduced a couple of sustainability instruments that were specifically developed for SMEs based on empirical experiences [94]. The sustainability assessment for enterprises (SAFE), for instance, served as a "dialog" tool to involve workers in the sustainability change process, so that they felt motivated to contribute to it. It consists of a questionnaire ("Is your company fit for the future?), that is administered at regular intervals and helps to identify the strengths and weaknesses of a company along with a list of suggestions for improvement, based on the collected information [95]. The other SME-specific tool is the sustainability evaluation and reporting system (SERS), representing an efficient overall CSR assessment that contributes to integrating non-financial and financial measures for improved responsiveness and stakeholder accountability. The three elements composing this system are the sustainability reporting system (annual, social and environmental reports), an integrated information system and sustainability KPIs [96]. Similar to EMA, sustainability management accounting (SMA) lays the data grounds for SMS, but unlike EMA it includes not only environmental but also social (e.g., training and education, health and safety are very important in SMEs) and economic performance costs. SMA yields benefits in the provision of higher quality data and indicators, which improved information consistency for better investment appraisal (by stakeholders) of the implementing companies. However, SMA's indicators are limited to reflecting the company's sustainability problematic aspects only. In order for SMA to consider the overall corporate sustainability effectiveness and to be used for continuous improvement, an article suggested integrating it with the composite sustainable development index (CSDI), providing a larger set of indicators [90]. For each of the three sub-indices of CSDI (economic, environmental, and social) a set of 5-15 indicators are chosen; they are thereafter normalized (since expressed in different units) and finally aggregated into the CSDI. The combination between SMA and CSDI provides a strong foundation for decision-making in SMEs through SMS [97]. In order to connect the operational SMA level to strategic SMS, a sustainability control system (SCS) can be applied [84].
Finally, the papers under analysis presented several guidelines and tools for sustainability reporting (also referred to as social and environmental reporting or SER) in SMEs, which are complementary to sustainability accounting [77]. The purpose of these reports is to communicate the performance of an organization (assessed using the previously mentioned tools) on all three TBL levels [91]. SER is mostly voluntary and based on financial accounting; it can also be disclosed in either a printed version for internal consultation, or as digital files on a firm's official website [98,99]. The most relevant SD guidelines, principles and standards are issued by international organizations: Global Reporting Initiative (GRI); the Prince's Accounting for Sustainability Project (A4S) for sustainable economy, business models and finance; the Sustainability Accounting Standard Board's (SASB) industry-specific standards on corporate financial materiality; the Principles for Responsible Investments (PRI) [91]; Impact Reporting and Investment Standards (IRIS); Global Impact Investing Report System (GIIRS); the SDG Action Manager by the UN Global Compact for developing SD goals within a firm's micro context, and B Impact Assessment (BIA), both hosted on B Lab's platform. The GRI set of standards is a globally recognized leader in the development of TBL for companies [77]. They include both universal (GRI 101: Foundation, GRI 102: General Disclosures, and GRI 103: Management Approach) and topic-specific standards related to the three TBL categories of disclosure. In addition to sustainability reporting, companies can also resort to integrated reporting, in adherence to the international <IR> framework by the International Integrated Reporting Council (IIRC). Unlike SER, IR is more of a concise communication, illustrating the process (strategy, governance, performance) of short-, mediumand long-term value creation through six forms of capitals (financial, material, socio-relational, intellectual-organizational, human and natural) to all internal and external stakeholders, and therefore is principally focused on "business sustainability" and additionally presents an organization's SD path. Both report types are valuable options for SMEs to disclose their path to SD, but convey different messages. The <IR> can replace the management report only and sheds some light on the resources (capitals) used for value creation, while the SER concentrates on the TBL aspect [91]. The other standardized instrument for measuring sustainability impact is, as previously mentioned, the BIA. Its comprehensive B Corp Index is a cumulative score obtained as a sum of questionnaire answers (both qualitative and quantitative) in five impact areas, namely workers, community, environment, customers, and governance. Companies obtaining a score of minimum 80 can apply for the B Corp Certification, which would require them to change their legal form into a Benefit Corporation within two years of after certification. However, apart from the certification, firms can use the Benefit Report on their own as an goal-setting tool for decision-making, for improving their sustainability and comparing their performance to the industry benchmark [77].

CSR Processes in SME Networks and Corporate Groups
In general, cooperative and community-based approaches to CSR (e.g., strategic alliances) between multiple SMEs, like in the case of networks/clusters and BGs, lead to major advantages for the individual firms taking part in them, not only in short-term economic terms but also from a long-term strategic perspective, by simplifying the implementation of sustainability management policies and helping to maintain the relative tools over time [94]. The following section analyzes how some of the sustainability tools from the previous section were extended to an entire group or network. For this purpose, it will be useful to understand how a BG relates to a network. Groups of companies, in fact, can be seen as having two layers of independent networks: the inter-organizational network, represented by the headquarters and branch offices (core BG), and the intra-organizational network, consisting of the core company, as well as suppliers and associated firms sharing the same goal. One of the articles used these definitions to illustrate the process of knowledge creation for the implementation of a network-wide environmental policy for "zero emissions". After the initial direction provided by top management in announcing the program for environmental management, middle management organized information flows about the new policy from branch offices to construction sites, hauliers and subcontractors in their allocated sites. This drove the arrangement of the inter-organizational network towards stronger ties (more qualitative information and cooperation, decreased opportunism) and density (shared norms and reputational monitoring), as well as effective externalization and socialization of BG's sense of CSR value. Then, middle management emphasized the centrality of corporate headquarters by serving as mediators between them, the construction managers of each branch office and the staff from the environmental improvement department. This bridging led to the sharing and combination of concrete knowledge for setting a proper path for CSR development. Next, branch office managers encouraged hauliers and subcontractors to design, test and share information on environmental management, externalizing the process to the entire intra-organizational network. Then, they helped supervise this process and provided operative training, internalizing this whole approach [100].
Another study showed how the endorsement of an EMS by an intra-organizational network of SMEs can be accomplished using a four-stage decision-making process, representing an adaptation of the ISO 14001 certification model. For the successful implementation of an EMS within an SME network, the network should already exist, the companies should not be competing against one another (for longer term network survival), a network promoter or facilitator should be appointed to carry out the development of the EMS, and it should be possible to decouple, for the innovation in question, the activities that are common across the network from those that address specific company issues. In the first stage, the management of each network company fully commits and accepts that it will take 6-12 months at least to initiate the project. This period will be utilized to build trust among the network members through discussions on projects that would appeal to all of them and, hence, can be achieved by the network as a whole (e.g., decreased environmental impact, and subsequently firm expenses). The second phase revolves around the implementation of those macro network activities, including the development of an environmental policy that shows each organization's commitment to the environment, the identification of the attributes (of products, services and activities) with the most impact on the environment, the awareness and understanding by all staff of any possible legal requirements, the establishment of environmental goals as per policy, and finally the planning of actions for achieving these targets. These first two stages follow the same structure across all network participants, while the remaining two have to be adapted to the peculiar situation of each firm. However, they will be carried out only if the network unanimously agrees to undergo extensive organizational change and work towards obtaining a certification, if satisfied with the results of the first two stages' in-depth analysis (3rd stage). In case a unanimous consent is reached, during the last phase each company will have to start implementing customized processes for establishing EMS responsibilities, providing employee training, managing operations in line with the environmental policy and objectives, developing procedures for identifying, correcting and preventing emergencies and problems, and periodically reviewing or auditing the EMS with the aim of improving it [73].
Concerning the final EMS phase of sustainability reporting, the legitimization BGs and networks are looking for from their CSR policy can be achieved by changing internal systems to include an auditability process. This way accounting technologies (group-wide information systems and data documentation, accounting instructions, books closing and internal controls), which are deemed an exemplary, authoritative and objective approach when it comes to reputation (towards external stakeholders, assurance providers or the top management), ensure that SER becomes an ongoing practice. The three essential elements of this integrated system, according to one of the studies, are data capture (information on data flow from site to group level/consolidation), data quality and reliability (at site accounting accuracy; its expertise can be translated to nonfinancial data), and a specific group social and environmental quality (SEQ) function (responsible for group level sustainability data preparation and external reporting). This function, with the auxiliary involvement of Group Finance and Group IT, sets BG's priorities on SER, so that business sites and areas give it due attention. The empirical research in question documented the stages a group went through on order to make SER auditable and functional across the entire core BG. The first step is to set up a proper information system, either an internally developed one or an external software solution, even one connected to an existing financial reporting platform. In the second stage, the Goup Finance is to develop specific accounting instructions to make data registration, processing and the whole SER reporting system auditable and aligned with the financial. These uniform instructions, however, may be considered unfit for some local contexts and not acknowledged by local SEQ staff (e.g., engineers). In these cases, despite the risk of losing the objectivity provided by accounting, Group SEQ opted to not control the intervention so meticulously, allowing local staff to follow their own locally adapted strategies to a certain extent. Third, social and environmental indicators, that are normally disconnected, should then be linked through financial accounting systems (based on double-entry bookkeeping, hence reliable) to ensure that data are reliable. Once defined, these indicators are disclosed in a CSR report on the website, as well as to governmental agencies and nongovernmental organizations, if required. Fourth, it should be arranged for Group SEQ to assist with the collection of data at sites and registration in the information system, and a standard for data documentation should be internally developed. Once these prerequisites are implemented, the internal control system, ensuring data completeness, can finally be established. For this purpose, the BG should experiment with MCSs, so as to find the most fitting system for its SER strategy. Controls can either be automated, thus built into the information system, or manual, meaning that the SEQ of the BG would perform some analytical procedures (e.g., performance review) to identify deviations between prior-and present-year data, then comment on the differences above 20% only. Alternatively, the BG may trust the assurance provider to design the control system [98].
CSR does not necessarily have to be limited to the group or network only. In fact, SME networks have great potential for increasing positive SD outcomes, especially when SMEs are embedded in the local territory. SMEs in these ethical territorial networks lead through their best practices and a collective vision the diffusion of CSR across the territory, known as territorial social responsibility (TSR). The focus of TSR is not only on shareholders but especially on the community (citizens and territory), which serves as both the main judge and beneficiary of socially responsible activities, such as improvements in the local quality of life and integration of economic events with socio-environmental considerations. TSR focuses on such important dimensions as participation, territorial identity, and the cultural CSR aspect (strategic and operative) for SD [101].
An example of this territorial approach to CSR is given by the implementation of the EMAS scheme, available to stand-alone firms, by a cluster (e.g., industrial districts, technological parks, other territorial agglomerations). This integration of environmental management at cluster level builds upon the co-opetition (cooperation among competing entities) between private companies and stakeholders located close to one another, as well as local governments. This can be considered a policy tool with a twofold purpose. On one hand, there is the pursuit of a more effective environmental performance within a certain jurisdiction (macro level), due to the narrowly focused traditional policy tools. On the other, environment managerial priorities that arise in SMEs also need to be taken into consideration (micro level), since they are simultaneously competing on a global issue for an opportunity to be globally recognized, despite the resource constraints. The transmission mechanism to the territorial area is guaranteed by the fact that SMEs in a cluster share suppliers, clients and similar environmental issues, and comply with the same legislations, thus making it possible for them to jointly come to solutions regarding their common territory, and exploit the resulting economies of scale (e.g., water purification systems used by all firms). The EMAS cluster approach, which is similar to the regional environmental management systems (REMS), is used for consolidating territorial, industrial and environmental policies in industrial clusters [72].

Discussion
The aim of the present review was to identify the processes through which aggregated companies (mainly in the form of SME networks and groups), which have a dominant influence in the global market, are able to effectively introduce and manage corporate sustainability practices, through integration with their control and management systems.
Insights were gathered on three different levels. On a general level, we tried to understand how corporate sustainability affects the performance of BGs and networks, at the same time investigating the geographic scope of each cooperative organizational type engaged in CSR. Then, through an overview of CSR tools used by SMEs, we identified the possible combinations of integrated MCS-sustainability systems and processes that could be potentially extended to firms engaged in a cooperative relationship. The third and last step consisted of finding out how to implement some of the previously evaluated systems as a network/group-wide strategy.
Concerning research interest by countries, emerging economies from the APAC area (South Korea and India, and to some extent China) were the main target for studies on CSR in BGs, while the European context (Norway, Germany, Italy, Sweden) spurred curiosity about the way networks interacted with CSR. The reasons behind such distributions of geographic focuses in the literature are related to the specific characteristics of each area.
As for emerging markets, in some cases (e.g., India, China) they face mandatory CSR models, making groups easily receptive of community as the purpose of their activities [66]. Additionally, BGs in these contexts are extremely aware of the liability of emergingness (LOE) causing negative reputational spills due to poor ethical practices and institutional voids, hence BGs frequently seek market legitimacy through sustainability-related practices [67]. And last, groups of companies have a prominent economic influence in emerging societies compared with other countries [67,69], which is mainly due to their unique relational structures (e.g., conglomerates and vertical integration in Korean chaebols) and regional business diversification across industries [32,102]. In the case of business networks, they are mainly associated with the European scene because they are perceived as one of the most efficient forms to pursue various strategic objectives (e.g., innovation, internationalization and cross-border cooperation) [103], due to their proven improved access to information and dialogue created within European projects [73]. There have indeed been many successful cases of European networks-especially in Germany (Konvoi approach), Italy (Ambiti Produttivi Omogenei-APO scheme), Spain, Denmark and Sweden [72]-that stimulated a growing interest by academics, policy makers and industrial analysts [104]. The European Union also provides extensive funding for implementing the afore-mentioned goals, which results in a high number of innovation projects led by networks [74]. Due to their importance, business networks are starting to be recognized as proper industrial policy instruments to be developed at European level, like in the Italian case of Business Network Contracts [105].
In terms of relationship between organization type and CSR intensity, among the papers that analyzed this occurrence, the majority found a positive correlation (63%). Both group affiliation (42%) and networks (21%) were found to accelerate the uptake of sustainability practices. No clear connection was found between country-specific contexts or listed status, as both negative and positive outcomes were associated with the same nations (e.g., South Korea, India) and featured both listed and non-listed firms.
A break-down of sustainability drivers revealed that the social dimension, in its employment, community and product responsibility components, was more developed than the environmental one. A possible explanation of this might be that such aspects can be achieved even through slight adjustments in employee wellbeing (e.g., annual monitoring through questionnaires), and hence lower expenses for organizations, more streamlined decision-making and managerial/directorial approval processes, which makes them almost immediately actionable. The same goes for donations to local institutions (e.g., cultural entities), the amount of which can be voluntarily decided based on the financial situation of the donating company. As for product responsibility, it is usually an integral part of the production-distribution process, because it is in a firm's interest to best present their product through warranties, marketing and after-sales assistance. Concerning the most impactful environmental factors, namely R&D, and management/reduction of materials and waste, they understandably require higher investments and a longer-term commitment, hence they are not promptly applicable, nor are the results immediate.
In Table 4, we compare the internal variables and interaction dynamics of BGs and networks that support the uptake of CSR, as summarized from the literature. Size and age (a1) increase resource endowment and, consequently, CSR investments. For BGs to obtain this advantage, they should either be larger or older (with experience incremented over time). The same also applies to networks, since BGs are form of it. However, in this case the situation is a bit more complex because the integration has to be done vertically across the value chain, while, in a group's case, despite firms being also legally independent, they are horizontally coordinated and controlled. The other internal variable is influence by member firms (a2). While both aggregations are inspired by fellow member companies that have adopted CSR practices first, once again the difference lies in the additional control dynamics present in BGs. Here, group promoters (family owners and holdings) both encourage and sometimes require the initiation of CS.
With regard to interaction with CSR, the three levels are macro (b1), that is to say, external interactions, mezo (b2), namely interactions between members, and micro (b3), that is, the impact of group/network structures on SME's CSR. On a macro level, the unitary brand identity of networks and BGs increases their international relevance, and therefore their chances of obtaining external investments. Besides, both stuctures provide support to governments in defining legal frameworks, priorities and industry standards locally and internationally. Nevertheless, the type of leadership exerted by BGs seems a bit more advanced, probably once again due to their unitary coordination and ownership: their power is quite political-like and, given their authority, they are able to lead by example a sustainability transition in industries or markets.
The mezo perspective suggests that strategic direction, spillover of synergies, and innovation expertise are common characteristics shared by members of both aggregation types. The differences are given once again by the horizontality or verticality in the respective organizational structures. On the one hand, group-level activities are all centralized and coordinated by headquarters, and firms are interdependent, which makes it easier to allocate resources more efficiently, as well as stimulate labor productivity homogeneously across the group through R&D projects. The only downturn in this case is that this homogeneity comes at the expense of those affiliates with the largest resource stock, leading to them sacrificing their own investment opportunities as well as a larger chunk of their endowment. Networks, on the other hand, present a looser but more varied structure, consisting of various value chain levels. This allows them to develop separate knowledge networks for each innovative project, through which they can then gain legitimacy for certifications or audits more easily. Their learning-action patterns can be as simple as exploiting new knowledge commercially and focusing on resource acquisition only, (grazer behavior), acquiring knowledge for the sake of translating it into internal processes (explorer behavior), or it can be more complex when attempting to strengthen external interaction ties for obtaining a benchmark for their existing innovative capacity, exploring and exploiting ideas at the same time (network behavior). Finally, these two collaborative organization forms yield the same positive effects in SMEs. They stimulate SMEs' active engagement in sustainability issues, transmitting more diligent schemes of vigilance to them, and this all helps smaller firms to differentiate themselves from their rivals. SME-specific limits dissipate, as they are able to attract talent, gain better access to markets by improving their capability to fulfill sustainability requirements (by buyers, financial institutions, etc.), optimize their technical and organizational capabilities, and potentially spread their CSR cost burden across numerous firms in the long term, improving earning management. Finally, all networks, but especially BGs, have an interest in adopting CSR in order to improve their brand equity, cumulatively and individually. In this sense, CS has an insurance-like effect that protects a BG's (international) reputation against group-specific externalities and reputational risks coming from family ownership. This initial evaluation of the advantages of BG/network CSR in SMEs, prompted us to further discover which sustainability-control-integrated instruments were specifically used by SMEs, and could then be potentially extended to the mezo context. The reason for including financial and managerial accounting and controls as a requirement for sustainability systems lies in the authority and reliability transmitted by them to sustainability management, which conversely cannot rely on rigorous and uniform standards.
Different levels of integration between MCSs and CSR were identified throughout the review, depending on the maturity of existing MCSs at the moment when a sustainability transition decision is taken. In one extreme, if MAC is well-established within an organization and any prior CS system is absent, sustainability can be "attached" to the existing system, without great modifications (traditional and contemporary MCS). In the other extreme, sustainability management can disrupt an existing MCS (integrated sustainability systems), by giving equal importance to CSR and MAC. The literature suggested decoupling, to a certain extent, sustainability accounting information from sustainability reporting; this way, it would be possible to keep track of the CS strategy, without mining the accuracy of managerial controls. If we consider MCSs as the economic variable in TBL, we can then cross-evaluate all the identified CSR tools according to their TBL type and degree of integration with the accounting and control system of the company. Figure 8 illustrates such cross-integrated categories, namely "pure" MCSs, sustainability-adapted MCSs, partial social and environmental management tools, and ultimately integrated sustainability systems. It is of note that the higher the cross-integration level, the higher the cost, complexity and requirements of the system. The boxes in the upper part represent MAC systems resulting from the integration with either partial or complete sustainability systems, while the arrows in the lower part provide an overview of sustainability-adapted MCSs. In such a perspective, traditional cost accounting and contemporary BCS (along with the broader PMSs which they belong to) can be considered proper integrated instruments once sustainable indicators are added (MFCA/ISO 14051, sustainability BSC and sustainability PMS respectively).
In terms of social management tools, SIA is a partial CSR model for assessing a firm's impact on its community. If integrated with MAC, it will result in SAA and SROI. There are also two partial social certification standards that can be adopted for helping improve a company's accountability towards its workers: OHSAS 18001 (mainly UK) and SA8000.
The largest variety of tools, however, could be attributed to the partial-environmental and sustainability-integrated categories. The procedures for both types could be similarly reorganized and combined into a unified logical process. For example, at the top of environmental management there is eco-efficiency, a managerial philosophy that strategically drives the planning and control cycles of EMS. This may take two main forms, ISO 14001 and EMAS, respectively, taking care of internal process improvements and public accountability, through the eco-mapping toolbox for on-site reviews. EMSs can be complemented by QMS/ISO 9001 (or its non-audited equivalent TQM) for ensuring internal quality, and integrated by EPM (e.g., EPM-KOMPAS for SMEs), in order to prompt enhancements through performance evaluation and support decision-making with additional information on a firm's strengths, weaknesses, opportunities and threats (SWOT analysis). When EMSs are combined with MACs, EMAs are obtained, with the function of monitoring both physical (e.g., materials, waste) and monetary flows. Benefits assessment, full-cost accounting, life-cycle costing and strategic planning are typical EMA instruments. Once the process of data collection and elaboration is set, the reporting phase can be supported by such schemes as the CDSB framework and the GHG protocol. Similarly, sustainability tools can be developed along the above-mentioned phases of management (ISO 26000, SMS), continuous performance assessment (SPM in general, and SME-specific SAFE), data monitoring (SMA, extending indicators on sustainability effectiveness through CSDI), and reporting (SER in general, and SME-specific SERS). The only difference is that the SCS was proposed as an additional control system to bridge strategy-based SMS and operational SMA. Concerning sustainability reporting, GRI was considered the most complete tool (containing both universal and TBL-specific standards), and BIA was also mentioned as an instrument that could either be used on its own for decision-making, goal-setting and industry sustainability benchmarking, or as a certification-leading route towards a more "serious" change (in terms of statute and legal form of Benefit Corporation). Finally, sustainability reporting was compared with integrated reporting: the latter is more of a concise managerial report (not replacing sustainability disclosure) providing detailed information on the types of capitals used for creating value (business sustainability), while the former delineates the TBL aspects of a firm, either partially or in its entirety. All the above-mentioned tools are extensively discussed in Section 4.2.2, should a more detailed explanation be useful.
phases of management (ISO 26000, SMS), continuous performance assessment (SPM in general, and SME-specific SAFE), data monitoring (SMA, extending indicators on sustainability effectiveness through CSDI), and reporting (SER in general, and SME-specific SERS). The only difference is that the SCS was proposed as an additional control system to bridge strategy-based SMS and operational SMA. Concerning sustainability reporting, GRI was considered the most complete tool (containing both universal and TBL-specific standards), and BIA was also mentioned as an instrument that could either be used on its own for decision-making, goal-setting and industry sustainability benchmarking, or as a certification-leading route towards a more "serious" change (in terms of statute and legal form of Benefit Corporation). Finally, sustainability reporting was compared with integrated reporting: the latter is more of a concise managerial report (not replacing sustainability disclosure) providing detailed information on the types of capitals used for creating value (business sustainability), while the former delineates the TBL aspects of a firm, either partially or in its entirety. All the above-mentioned tools are extensively discussed in Section 4.2.2, should a more detailed explanation be useful. Once the possible types of CSR tools applicable in the micro-SME context have been identified, along with their sequence of use, we wanted to understand how BGs and networks introduced and applied either of them across all member firms (mezo perspective) in a systematic fashion. The various steps gathered from the papers in this section were then reorganized in a logical flow, in an attempt to reconstruct a possible comprehensive process that either of the aggregated forms could apply in their transition towards sustainability. Despite some methods being empirically found in groups and other in clusters, this should not pose a problem for the scope of this analysis, as the focus is not on control or ownership, and also because both forms have a similar nature of coordinating multiple and differentiated businesses. In this review, partial environmental tools were replaced with sustainability terms. This was acceptable because the analysis in the previous section showed the similarity of the structures followed by both types. The logical process that resulted from the assessment of the articles consisted of the following stages (Table 5).
First, an initial commitment to and mutual acceptance by all member firms of the objective to build a sustainability management system. During this initial phase, (which can last up to 1 year) in order to build reciprocal trust, fellow companies should collectively pick a project that is both interesting for them and stimulating but achievable by the network or group.
Second, after the first year, group or network-wide preliminary activities should be set in place. The whole process will be initiated by executives, defining a proper sustainability policy, along with the most important CSR topics for the organization (materiality analysis). After all workers have studied and acknowledged the related legal requirements, it will be possible to determine sustainability targets and practical action plans to reach them. The role of middle management is fundamental in this case, as it will serve as a bridge for information flows among the holding, subsidiaries and other participating firms, such as suppliers.
The third step consists of an evaluation of the first two phases. If all the companies in the BG or network feel satisfied with these early results, this will be a decisive stage for the entire network or BG. This is because, at this point, they can opt to either undergo a serious organizational change or abandon the idea. The decision does not necessarily have to do with a certification but can consider the introduction of a different but complex sustainability system at aggregated firm level. In any case, whatever the decision, it has to be unanimous.
Once firms come to a resolution, they can move on to the fourth stage, which consists of them adopting the necessary firm-level actions towards certification or sustainability system. A prerequisite to this phase is the identification or the creation of a network facilitating or appropriate Group SEQ function, which should cooperate with and be supported by the entity's Finance and IT functions. The responsibilities and data capture process will be established at each micro level, along with data quality and communication flow. Other firm-specific activities include employee training, management of operations in conformity to the general sustainability policy, the development of procedures for managing and preventing issues and emergencies. The newly applied system should be periodically reviewed in order to improve it.
Concerning the fifth phase, before concentrating on the design of the chosen internal control system, in order to make sustainability reporting auditable, a series of prerequisites have to be settled down, namely, the establishment of an internal or external information system and the development of specific accounting instructions, which will then be used to link social and environmental indicators so that they can be disclosed on the company website. The group/network SEQ's task will be to assist local branches with data collection and registration at sites. In addition, they will need to develop an internal data documentation standard for auditable reporting. Finally, the extension of CSR through the territorial approach of TSR, not only will help to improve local community and environmental performance in a specific jurisdiction, it will also maintain individual firm focus based on their individual sustainability priorities. Two extremely useful tools, providing excellent support in the diffusion of CSR to the community, are the EMAS scheme and the regional EMS. Table 5. Process-flow for integrating sustainability initiatives within a group or network.

Stage Activity Description Actors
(1) Project initiation: commitment and acceptance Consolidate territorial, industrial and environmental policies in industrial clusters 3.
Simultaneously take into consideration individual firms' priorities (micro level)

Conclusions
The aim of this systematic literature review was to investigate the success behind the adoption of a corporate sustainability and responsibility system by cooperative forms of organization, such as corporate groups and business networks.
To begin with, an evaluation of relations and influences unveiled that both organizational forms have positive effects on CSR development on three levels. With respect to external environment, both yield a certain "political power" when supporting governments in setting industry environmental standards. Concerning member-firm interactions, sustainability-oriented innovations are stimulated by centralized coordination and control in BGs, on one hand, and vertically integrated knowledge networks, separately developed for each innovative project, on the other. Moreover, their micro impact on an individual SME's CSR allows the latter to increase its reputational gains, mitigate CSR expenses, and optimize organizational capabilities. This study also found that both partial (social, environmental) and complete sustainability systems were susceptible to being integrated with management accounting in SMEs, making it an almost implicit tool for proper CSR.
Finally, by gathering the empirical literature on the sustainability transition of networks and groups, it was possible to trace a complete introduction plan that operators could resort to for initial assistance. The six steps of this process are (1) project initiation, commitment and acceptance, (2) implementation of network/group-wide preliminary actions, (3) decision to undergo ample change management (e.g., certification or general sustainability transition), (4) implementation of firm-level activities, (5) auditability of reporting for better legitimization, (6) transition from CSR to territorial social responsibility (optional).
This paper additionally provides some practical implications to managers of companies (especially SMEs) that are a part of groups or networks. Firstly, it gives some evidence on the specific characteristics of aggregated firms that can place them at an advantage in pursuing a sustainability management strategy, specifically, the size and internal influence. The size given by the plurality of companies allows each member to leverage a wider base of resources and skills from different business areas to invest in CSR. Concerning influence, headquarters and/or fellow members prompt each firm to engage in CSR by example, through control or peer pressure. Other facilitating factors are experience, international negotiating power, a common long-term strategic direction, and the removal of operational barriers. Along with this, a summary of benefits at each level of BG/network interaction should help companies to acknowledge the importance of CSR for business development and reputational growth. The most impactful corporate sustainability variables are then briefly analyzed, in order to provide an idea of the types of actions that companies can either take immediately or in the long run. Additionally, the paper presents an overview of CSR-MCS integrated tools that are applicable in various contexts, depending on the organization's complexity, establishment of pre-existing internal systems, and resource availability. Lastly, managers can follow the steps from the developed framework in order to pursue a sustainability change management and conform all member firms to a unitary CSR system.
Despite the systematic retrieval of all relevant publications, the study may still have limitations due to the risk of omitting applicable articles. Other limitations relate to the fact that findings may not be generalizable because of how heterogeneous the included papers were (emerging vs. developing markets, listed vs. non-listed firms). The current evidence base on sustainability in BGs formed by SMEs is extremely limited (n = 6). Therefore, future research could empirically explore this particular situation, preferably in the context of developed economies, since all the literature used for content analysis was focused on emerging markets. Further, there is also a need for a wider research base on case studies of business groups and networks implementing CSR across multiple firms. Finally, an additional review on how the banking and financial sectors develop their CSR activities would be an interesting topic to explore.        Abbreviations: 2SLS = two-stage least squares; BSC = balanced scorecard; C = conceptual research; CBA = cost-benefit analysis; CSR = corporate social responsibility; CER = corporate environmental responsibility; CSD = corporate social disclosure; CSDI = composite sustainable development index; CSP = corporate social performance; CSS = corporate sustainability strategy; EDA = environmental disclosure and accountability; EI = environmental innovation; EMA = environmental management accounting; EMS = environmental management system; Eql = empirical qualitative research; Eqn = empirical quantitative research; ERC = earnings response coefficient; ESA = environmental and sustainability accounting; ESG = non-financial disclosure; FAHP = fuzzy analytical hierarchy process; FDM = fuzzy delphi method; FIS = fuzzy inference system; GRA = grey relational analysis; IMC = integrated marketing communication; MAC = management accounting and control; MCDM = multi-criteria decision making; MCS = management control system; MEC = monitoring and environmental control; MFCA = material flow cost accounting; NPV = net present value; OLS = ordinary least squares; PLS = partial least square; QMS = quality management system; RST = rough set theory; SAFE = sustainability assessment for enterprises; SD = sustainable development; SER = social and environmental reporting; SERS = sustainability evaluation and reporting system; SIA = social impact assessment; SMA = sustainability management accounting; SMS = sustainable management system; SOI = sustainability-oriented innovations; SPMS = sustainable performance management system; TOPSIS = technique for order preference by similarity to ideal solution. References in grey were further analyzed in their content (Section 4.2).