Bibliometric Analysis of SARS, MERS, and COVID-19 Studies from India and Connection to Sustainable Development Goals

: India is ranked ﬁfth in the world in terms of COVID-19 publications accounting for 6.7% of the total. About 60% of the COVID-19 publications in the year 2020 are from United States, China, UK, Italy, and India. We present a bibliometric analysis of the publication trends and citation structure along with the identiﬁcation of major research clusters. By performing network analysis of authors, citations, institutions, keywords, and countries, we explore semantic associations by applying visualization techniques. Our study shows lead taken by the United States, China, UK, Italy, India in COVID-19 research may be attributed to the high prevalence of COVID-19 cases in those countries witnessing the ﬁrst outbreak and also due to having access to COVID-19 data, access to labs for experimental trials, immediate funding, and overall support from the govt. agencies. A large number of publications and citations from India are due to co-authored publications with countries like the United States, UK, China, and Saudi Arabia. Findings show health sciences have the highest number of publications and citations, while physical sciences and social sciences and humanities counts were low. A large proportion of publications fall into the open-access category. With India as the focus, by comparing three major pandemics—SARS, MERS, COVID-19—from a bibliometrics perspective, we observe much broader involvement of authors from multiple countries for COVID-19 studies when compared to SARS and MERS. Finally, by applying bibliometric indicators, we see an increasing number of sustainable development-related studies from the COVID-19 domain, particularly concerning the topic of good health and well-being. This study allows for a deeper understanding of how the scholarly community from a populous country like India pursued research in the midst of a major pandemic which resulted in the closure of scientiﬁc institutions for an extended time.


Introduction
The present COVID-19 pandemic has affected every socioeconomic sector. Globally, everything from manufacturing to entertainment has been affected. Academia is no exception. In fact, most universities globally have suspended on-campus activities and have moved online [1]. While teaching practices can to some extent be mitigated by digital interventions and online teaching, research is more complex and often requires campus collaboration and laboratory facilities [2]. While safety norms may require research to be suspended, research is also an essential first step in understanding and fighting this pandemic. Given that it is a novel virus, research regarding its characteristics is integral to developing mechanisms for fighting it. Similarly, methods of detection, isolation, protection, etc., also need to be developed at a fundamental level. In addition, given the scale of the pandemic, research on its effects on other aspects ranging from the global supply chain to mental health needs to be understood and any adverse effects mitigated [3,4]. In light of all these needs, researchers across the world have continued their work even under these challenging conditions, generating an impressive volume of research during this time [5]. In as much as the rest of the Scandinavian countries combined. While some error in these numbers is possible due to insufficient testing, it is safe to assume that the lockdown has aided in mitigating the adverse effects of COVID-19 to a significant extent in the country. While this lockdown certainly affected educational institutions from schools to higher research centers, it is interesting to note that India has contributed significantly to research regarding the pandemic. In fact, despite the stringent lockdown and continued travel restrictions, India ranks fifth in a number of publications related to COVID-19 worldwide.
This study focuses on academic literature on COVID-19 globally, and the performance of the Indian Scientific community in comparison to its counterparts. The study compares how India's overall scientific output in the year 2020, and research specific to COVID-19 for the same period can be valued relative to global output. This is done by comparing several parameters such as publications, citations, international collaborations, journal sources, funding, etc.
According to Oxford COVID-19 Government Response Tracker (OxCGRT), India had one of the strictest lockdowns during the year 2020. The average monthly stringency score (77.9) was the highest for India for more than nine months in the year 2020. There was complete closure of educational institutions with researchers having very limited access to labs to perform experiments. The mood of the nation was also somber with spiraling cases and deaths.
Yet, against this backdrop, authors from India showed phenomenal resilience and conducted research about COVID-19 with whatever forms of data and funding were available. While we are ranked No. 2 in the world for COVID-19 cases, it is very heartening to observe that we are ranked No. 5 in the world for COVID-19 studies. It is this aspect that prompted us to analyze the scientific contribution of researchers from India. Our choice to use bibliometric methods was guided by the fact that we had to examine a large number of publications. Additionally, using Bibliometrics techniques we were able to analyze publications at author, article, journal, country level and compare with worldwide data. Something unique about our study, probably the first one to be completed at the country level, was the comparison of three major epidemics-SARS, MERS, and COVID-19-which draws interesting parallels by using bibliographic couplings and co-citation analysis. Finally, connecting the COVID-19 studies with UN Sustainable Development Goals (SDG) brings in the much-needed relevance of the research.
We have structured the paper as follows: Section 2 discusses the study methodology using bibliometrics including the search strategy. Section 3 presents the results and discussion in terms of publications, citations, institutions, and countries including the network analysis with a visual representation of bibliographic data and how COVID-19 studies are connected to sustainable development. Finally, Section 4 is about the conclusions of the study with limitations and future directions.

Study Methods
We followed a two-step process to cover our study objectives. In the first step, we performed the scoping review using the Arksey and O'Malley framework [19]. A scoping review is a research methodology effective for summarizing and covering broad research topics, comprising a high number of previous studies, publications, methods, theories, or evidence [20]. Most importantly, a scoping review can pinpoint research gaps without losing research robustness and rigorous quality assessments [21]. In this step, we proposed research questions; identified the data source and software mapping tools; proposed search strategies; retrieved data from the database. Then in the second step, we performed a bibliometric analysis of the data from scoping review.
Past research performance can be analyzed using qualitative and quantitative methods like literature reviews and meta-research when the quantity of publications and corresponding citations are small. Thanks to social media platforms, researchers are investigating alternative metrics, or Altmetrics, for a more comprehensive perspective of research impact beyond the traditional indicators like publications, citations, etc. [22]. Sourced from  Altmetrics estimate research impact through mentions on Twitter, Mendeley, Online mentions in blogs, etc. However, Altmetrics also has its own limitations: a publication  can have high attention because readers are disputing its findings; researchers who are  very active on social media with a large following might have higher attention compared  to those who are not active on social media. It is more appropriate and relatively easy to use bibliometric methods to examine a large number of publications which is the case with our study analyzing over 93,000 publications. Bibliometrics is a set of methods to measure scholarly impact from research publications and can easily be scaled from micro (author, article, journal) to macro (subject area, country, world) level. Additionally, with bibliometric science mapping techniques, one can examine how different research themes, author and journal-level publications and citations, institutions, and countries are linked to one another and visualize the results spatially.
Analyzing Indian publications on SARS-CoV-2 as found in the WHO COVID-19 database [37], results showed a considerable increase in the number of publications from Indian authors on the topic as compared to SARS and MERS. Most of the authors came from government medical institutions, probably an indication of early access to COVID-19 related data. The WHO COVID-19 database included only curated publications and did not include preprint servers. The bibliometrics study [38] mainly focused on the growing contribution of the Arab world to global research on COVID-19 with a focus on Saudi Arabia which had the highest number of publications. A total of 143,975 publications reflecting the global overall COVID-19 research output, between December 2019 and March 2021 were retrieved from the Scopus database. The main research themes identified by the study were related to public health and epidemiology; immunological and pharmaceutical research; clinical diagnosis and virus detection. Another bibliometrics study [39] analyzed publications from Iranian researchers and reported that though most of the studies were related to epidemiology and public health, more collaboration with international researchers is needed.
Two other studies [40,41] compared the research work on SARS, MERS, and COVID-19 using both proprietary database and preprint servers like bioRxiv and medRxiv. Using Natural Language Processing techniques, very early COVID-19 data was collected from multiple sources. Analyzing a total of 13,945 publications and seven datasets, the study reported that the quality of research as indicated by citations were substantially higher for COVID-19 studies. COVID-19 bibliometric study [42] focusing on Latin America, used the Scientific Electronic Library Online (SciELO) database to identify authors, publications, and journals. They reported that since many of the publications were in the Spanish language, they were not adequately represented in international journals. However, the findings of this study further support the assertion that the contents of bibliometric databases have developed a definitive bias toward the English language [

Data Sources and Selection of Bibliometric Software Mapping Tools
For our bibliometric analysis, we chose Scopus, which is a large abstract and citation database with over 74 million records from 23,500 peer-reviewed publications in the fields of science, technology, medicine, social sciences, and arts and humanities [43,44]. The VOSviewer [45] software was used to analyze the co-occurrence network for keywords, co-authorship network [46], citations [47], and bibliographic coupling [48]. The h-index [49] which is widely used in bibliometric studies [50] was also analyzed.
In our study, we also considered data sources, https://www.worldometers.info/ coronavirus (accessed on 1 January 2021) for data on COVID-19 deaths and cases, as well as www.scimagojr.com (accessed on 1 January 2021) for Scimago Journal Rankings (SJR). The average of the daily score of the Oxford Stringency index was taken from (https://COVIDtracker.bsg.ox.ac.uk/, accessed on 1 January 2021) for the period as of 31 December 2020 with a minimum threshold of a daily score of 30 was set to account for varying dates of lockdown measures.

Search Strategy
Publications were retrieved via a topic search (title/abstract/keywords) from the Scopus database for the year 2020 as of 1 January 2021. The following search queries were created with the goal of reducing the amount of data overlap across the SARS, MERS, and COVID-19 datasets [40]. In order to eliminate overlap, relevant phrases from various literature were joined with the Boolean operator "AND NOT" in each search. The time period for each search was determined by considering the year in which each virus epidemic occurred.
• SARS: (TITLE-ABS-KEY ((("Severe acute respiratory syndrome" OR "SARS") AND (coronavirus*)) OR ("SARS virus" OR "SARS disease" OR "Severe acute respiratory syndrome disease" OR "Severe acute respiratory syndrome virus" OR "SARS-Cov")) AND NOT TITLE-ABS-KEY (("COVID" OR "nCov" OR "COVID-19" OR "COVID19" OR "SARS-Cov-2" OR "Severe acute respiratory syndrome-2" OR "MERS" OR "middle east respiratory syndrome"))) AND PUBYEAR > 2001. • MERS: (TITLE-ABS-KEY ((("Middle east respiratory syndrome" OR "MERS") AND (coronavirus)) OR ("MERS-Cov" OR "MERS virus" OR "MERS disease" OR "Middle east respiratory syndrome virus" OR "Middle east respiratory syndrome disease")) AND NOT TITLE-ABS-KEY (("nCov" OR "COVID-19" OR "COVID19" OR "SARS-Cov" OR "SARS-Cov-2" OR "SARS" OR "Severe acute respiratory syndrome"))) AND PUBYEAR > 2011. • COVID-19: TITLE-ABS-KEY ("COVID-19" OR "COVID19" OR "coronavirus disease 2019" OR "2019-nCov" OR "Novel Coronavirus" OR "Novel Corona virus" OR "SARS-Cov-2") AND PUBYEAR > 2018. The United States had both the highest number of cases and deaths per million population while Australia had the lowest score in the stringency index. India has the highest score of 78.7, which may provide a possible explanation for a low number of cases and deaths per million population. China had the highest number of citations per publication possibly due to the effect of the first outbreak of the COVID-19 virus and the easy availability of data among Chinese authors to write papers and cite each other's work. A total of 6223 publications, with affiliation as India for at least one author, were found for the year 2020. These publications were written by 12,417 authors and published in 1370 sources. Out of this, 2513 (40.3%) publications had at least one citation in Scopus, providing a total of 20,816 citations. This resulted in average citations per paper of 3.3 and citations per author of 1.7.

Bibliometric Analysis
It is seen that Indian authors have collaborated with researchers in 147 countries, with 4667 (74.9%) publications having international co-authorships. This indicates a healthy international collaboration during the pandemic. The largest number of collaborations were with the United States, followed by China, UK, Saudi Arabia, Japan, Italy, Columbia, and South Korea, as seen in Table 2. These seven collaborating countries accounted for 1866 (30.1%) publications. For publications from India, the number of citations is highest for publications from United States followed by those from China, UK, and Italy. The number of citations per publication varies from 22.7 for Nepal to 7.1 for the United States. However, given that a larger number of publications are generated in Italy, China, the US, and the UK, researchers have diverse options for citing work from these countries, thereby moderating the number of citations per publication. A very limited number of publications from Nepal and Japan (58 and 70 papers each) leads to a larger number of citations on the ones available. The quality of research work can therefore not be assessed based on the same metric.
Although the number of publications and citations related to SARS and MERS increased since the respective outbreaks took place, Indian authors took more interest in them only in the year 2020 when COVID-19 happened, as shown in Table 3. The surge in coronavirus research triggered by the COVID-19 outbreak, on the other hand, appears to be on a scale that is unprecedented in the history of coronavirus research, and probably perhaps in the history of science. Analyzing the total number of COVID-19 related publications globally, it is seen that 50,865 (54%) are research "Articles", as shown in Table 4. The trend is similar in India with 3186 (51%) publications. Furthermore, in India, "Letters and Reviews" add up to 2392 (38%), while the share of such publications is only 25,203 (27%) globally. Other publications take up 10% of the overall share in India and 19% globally. It should be noted that such a high share of non-article publications is abnormal, and generally, 71% of all publications in India were articles in the year 2020. This higher fraction of non-articles related to COVID-19 may be attributed to the time required for the peer review process as softer letters and reviews do not have to pass that hurdle.  Table 5. Both private and public institutions are represented well in the top-10 in the world for institutions with the most COVID-19 publications.
When comparing the publications and citations achieved by public and private institutions in India, the former has a clear upper hand, as shown in Table 6. A much larger number of publications were produced by public medical institutions such as AIIMS and PGI Chandigarh. The private medical institute with the highest number of publications is Saveetha, where the medical and dental departments together roughly match the number of publications by PGI Chandigarh. However, in terms of the number of citations, public medical institutes are far ahead of private institutes. IVRI (Veterinary) has 15 citations per publication while ICAR New Delhi has 14.4 citations per paper. Tata Memorial has Sustainability 2021, 13, 7555 8 of 20 a citation per publication score of 6.2. However, among private sector institutes, the highest citation per publication is 3.7 for CMC Vellore. Clearly, public medical institutes have exceeded their private counterparts in academic excellence in this area. This is partly due to government funding and ease of access enjoyed by these institutes with regard to viral samples and data for clinical studies. When we compare the three outbreaks, we observe that the research interest from Indian institutions in conducting coronavirus studies has increased by a factor of three from 160 in SARS to 249 in MERS to 523 institutions for COVID-19. This interest is also reflected in the very large number of publications and citations related to COVID-19 studies.

Most Influential Journals
A list of journal sources with a number of publications, citations, Scimago Journal Rankings (SJR), and h-index are listed in Table 7. The highest citation per publication is achieved by the Journal Science of the Total Environment which is a Q1 journal with a high h-index of 224. Similarly, the Journal Diabetes Research and Clinical practice, another Q1 journal with a high h-index of 107, has over 23 citations per publication. The Journal of Biomolecular Structure and Dynamics, a Q2 journal, with a relatively moderate h-index of 32 has the highest number of COVID-19 related publications while Nature Medicine and The Lancet, the most reputed journals in the field, have a very limited number of COVID-19 related publications (four each), likely owing to the highly stringent review process and high article processing charges. When we observe the data on studies about SARS, MERS, and COVID-19 published in journals, we see a large surge in the number of different journals where COVID-19 studies were published. While SARS studies were limited to 124 journals, MERS had 310 while COVID-19 studies were published in over 1370 journals.

Top Performing Subject Areas
A majority of publications related to COVID-19 are from health sciences (76,657, 82.1%), with medicine alone accounting for (64,505, 69.3%) globally. The proportion is slightly lower for India, with 4165 (67.2%) publications coming from health sciences, as indicated in Table 8. Of these, 3790 (91.4%) are from medicine. However, life sciences also contributed a healthy 43% of the total share of COVID-19-related articles, while physical sciences and social sciences made up the rest at 29% and 15% respectively. It is also interesting to note that within physical sciences, computer science and engineering which are technology-oriented constitute a higher share than that of pure sciences such as chemistry or physics. Within social sciences, art and humanities contribute the least while pure social science contributes the highest share.

Co-Authorship Network and Publications
In order to study the collaboration networks of authors, we used co-authorship network analysis which is a widely accepted practice in bibliometric studies [51].
In a network graph, each author is represented by a bubble and the bubble size is proportional to the number of publications attributed to the author. Two authors who have collaborated on any paper are linked by a line, with each line representing collaboration on a single paper. Colors indicate clusters of authors that are relatively strongly connected by co-authorship links and authors with a high degree of collaboration are located close to each other.
We investigated the co-authorship network in India, with authors having at least 15 COVID-19 related publications. This resulted in seven major collaboration clusters with a total of 132 authors, as can be observed in Figure 1. The important clusters in the co-authorship network of authors shown in the following colors: red corresponds to authors "kumar a", "kumar s", "sharma p"; green color to author "gupta n"; yellow to author "das s" and finally blue to "dharma k". As indicated by the size of the bubble, those are leading authors who produced the highest number of papers in collaboration with others.

Co-Citation Network of Authors
Similarly, we investigated the co-citation network of Indian authors with at least five citations. Note that co-citations indicate formats that contain ideas, experiments, or methods that have received peer recognition, as evidenced by their co-occurrence of citations [52].
This network analysis resulted in six clusters, where 124 out of the 12,417 authors had at least five citations, as shown in Figure 2. Each author is represented by a node whose size is proportional to the number of citations. The important clusters of citations appear in the following colors: red corresponds to author "dharma k"; green to author "chakrabarthi s"; yellow to author "gupta n" and finally blue color to "sharma s". As indicated by the size of the bubble, those are leading authors with the highest number of citations. The important clusters in the co-authorship network of authors shown in the following colors: red corresponds to authors "kumar a", "kumar s", "sharma p"; green color to author "gupta n"; yellow to author "das s" and finally blue to "dharma k". As indicated by the size of the bubble, those are leading authors who produced the highest number of papers in collaboration with others.

Co-Citation Network of Authors
Similarly, we investigated the co-citation network of Indian authors with at least five citations. Note that co-citations indicate formats that contain ideas, experiments, or methods that have received peer recognition, as evidenced by their co-occurrence of citations [52].
This network analysis resulted in six clusters, where 124 out of the 12,417 authors had at least five citations, as shown in Figure 2. Each author is represented by a node whose size is proportional to the number of citations. The important clusters of citations appear in the following colors: red corresponds to author "dharma k"; green to author "chakrabarthi s"; yellow to author "gupta n" and finally blue color to "sharma s". As indicated by the size of the bubble, those are leading authors with the highest number of citations.

Co-Occurrence Network of Keywords
When searching for scientific publications, a keyword search is usually the easiest way to access relevant information. Therefore, appropriate keywords that provide a reasonable description of the work allow the study to reach a wider audience. To carry out a keyword-based analysis, keywords described by at least five publications were chosen, and a co-occurrence network was constructed. The unit of analysis has also been set to all keywords (this includes both author and index keywords) and the method of counting was set to full counting.
These results are shown in Figure 3, where it can be seen that works published by Indian authors have employed a wide range of keywords, ranging from those related to virology and epidemiology to those associated with mental health, air pollution, and lockdown. This indicates that the work generated in India spans multiple disciplines and covers a diverse gamut of topics related to the pandemic.
With respect to each of the three epidemics, distinct clusters of keywords were identifiable but there were commonalities among them. All three epidemics had a cluster with terms such as a pandemic, infection control, viral, epidemic, virus transmission associated with general public health, and disease outbreak. Another cluster had terms that are generally associated with virology studies like virus protein, virus entry, chemistry, amino acid sequence, virus genome, protein binding, etc. Figure 3c shows that the COVID-19 studies resulted in four clusters which are described below: • Cluster 1 (red) shows high-frequency keywords related to epidemiological and public-health studies on COVID-19, such as: o Pandemic, coronavirus disease 2019, public health, health care personnel, infection control, mental health, quarantine, disease transmission.
• Cluster 3 (blue) involves high-frequency keywords associated with clinical studies, signs, and symptoms of the disease, as well as pharmacological and nonpharmacological interventions for COVID-19, for instance:

Co-Occurrence Network of Keywords
When searching for scientific publications, a keyword search is usually the easiest way to access relevant information. Therefore, appropriate keywords that provide a reasonable description of the work allow the study to reach a wider audience. To carry out a keywordbased analysis, keywords described by at least five publications were chosen, and a cooccurrence network was constructed. The unit of analysis has also been set to all keywords (this includes both author and index keywords) and the method of counting was set to full counting.
These results are shown in Figure 3, where it can be seen that works published by Indian authors have employed a wide range of keywords, ranging from those related to virology and epidemiology to those associated with mental health, air pollution, and lockdown. This indicates that the work generated in India spans multiple disciplines and covers a diverse gamut of topics related to the pandemic.
With respect to each of the three epidemics, distinct clusters of keywords were identifiable but there were commonalities among them. All three epidemics had a cluster with terms such as a pandemic, infection control, viral, epidemic, virus transmission associated with general public health, and disease outbreak. Another cluster had terms that are generally associated with virology studies like virus protein, virus entry, chemistry, amino acid sequence, virus genome, protein binding, etc. o Hydroxychloroquine, remdesivir, azithromycin, cytokine storm, chloriquin, angiotensin enzyme, dysphea, respiratory failure, comorbidity, fever, fatigue.
• Cluster 4 (yellow) includes terms relevant to measures of disease control and spread prevention such as:

Bibliographic Couplings among Countries
Bibliographic couplings are described by [53] which proposes that two papers referring to a third paper are highly related, so they should be grouped into a cluster solution. Figure 4 presents the bibliographic coupling among countries, where any country with a minimum of five publications with an Indian collaboration was considered. When the three maps of co-authorships are compared, a pattern of author engagement emerges from the area where each virus outbreak began. In all three epidemics, studies produced by scholars linked with Indian institutions are well represented. However, the figure also illustrates frequent coupling among other countries such as England, Germany, and the Netherlands for COVID-19 studies with United States, United Kingdom, Saudi Arabia, Japan, Italy, Columbia, and South Korea as top collaborators. Overall, the number of collaborating countries has increased from 28 for SARS to 81 for MERS and, reached a total of 154 for COVID-19.  Figure 3c shows that the COVID-19 studies resulted in four clusters which are described below:

•
Cluster 1 (red) shows high-frequency keywords related to epidemiological and publichealth studies on COVID-19, such as: Pandemic, coronavirus disease 2019, public health, health care personnel, infection control, mental health, quarantine, disease transmission.
• Cluster 4 (yellow) includes terms relevant to measures of disease control and spread prevention such as: COVID-19, coronavirus, lockdown, air pollution, China, WHO.

Bibliographic Couplings among Countries
Bibliographic couplings are described by [53] which proposes that two papers referring to a third paper are highly related, so they should be grouped into a cluster solution. Figure 4 presents the bibliographic coupling among countries, where any country with a minimum of five publications with an Indian collaboration was considered. When the three maps of co-authorships are compared, a pattern of author engagement emerges from the area where each virus outbreak began. In all three epidemics, studies produced by scholars linked with Indian institutions are well represented. However, the figure also illustrates frequent coupling among other countries such as England, Germany, and the Netherlands for COVID-19 studies with United States, United Kingdom, Saudi Arabia, Japan, Italy, Columbia, and South Korea as top collaborators. Overall, the number of collaborating countries has increased from 28 for SARS to 81 for MERS and, reached a total of 154 for COVID-19.

Bibliographic Couplings of Journal Sources
Similarly, we studied the bibliographic couplings of journal sources for all three pandemics. We observe that the journal sources have increased dramatically from 124 journals for SARS to 310 journals for MERS, up to a large 1370 journals for COVID-19. Journal of Biomolecular structure and Indian Journal of Medical Research is found common for all three pandemics, as seen in Figure 5. We also notice that MERS studies were published in specialty journals like the Journal of Virology, Human Vaccines and Immunotherapy, and Frontiers in Microbiology.

Bibliographic Couplings of Journal Sources
Similarly, we studied the bibliographic couplings of journal sources for all three pandemics. We observe that the journal sources have increased dramatically from 124 journals for SARS to 310 journals for MERS, up to a large 1370 journals for COVID-19. Journal of Biomolecular structure and Indian Journal of Medical Research is found common for all three pandemics, as seen in Figure 5. We also notice that MERS studies were published in specialty journals like the Journal of Virology, Human Vaccines and Immunotherapy, and Frontiers in Microbiology.

Bibliographic Couplings of Journal Sources
Similarly, we studied the bibliographic couplings of journal sources for all three pandemics. We observe that the journal sources have increased dramatically from 124 journals for SARS to 310 journals for MERS, up to a large 1370 journals for COVID-19. Journal of Biomolecular structure and Indian Journal of Medical Research is found common for all three pandemics, as seen in Figure 5. We also notice that MERS studies were published in specialty journals like the Journal of Virology, Human Vaccines and Immunotherapy, and Frontiers in Microbiology. When it comes to COVID-19 studies, we evaluated the journals with a minimum of ten publications from a total of 1370 journal sources that Indian authors had published. This resulted in 97 items divided into seven clusters, as shown in Figure 5 (bottom). As expected, most of the highly cited papers appeared in high-impact factor journals indicating their higher research quality. Most publishers followed an accelerated review process, online-first policy and provided open access to such publications.

COVID-19 Studies Connected to Sustainable Development
We also evaluated the connections between COVID-19 studies and sustainable development. In this regard, we used 17 United Nations Sustainable Development Goals (SDG), adopted in 2015, as a proxy for sustainable development. The COVID-19 pandemic has had an important impact across all the SDGs, for instance through reduced CO2 emissions because of the lockdowns [54], with clear implications on SDG 13 (on climate action). However, a number of studies [55,56] suggest that the situation may progressively return to the pre-pandemic levels, in the context instance of aviation and its impact on the environment. Several studies suggest that the symptoms associated with COVID-19 may be exacerbated due to increasing pollution levels [57], a fact that closely connects SDGs 3 (on health) and 11 (on sustainable cities). Another important aspect regarding the management of the COVID-19 has to do with the digital-contact-tracing apps, which aimed at achieving better control of the pandemic, with a positive impact on SDG 3, but could potentially exhibit challenges [58][59][60] in the context of SDGs 10 (on reduced inequalities) and 16 (on strong institutions). The connections reported above have a clear relation with the results presented in Table 9, where the number of Indian COVID-19 articles and their citations related to each of the 17 SDGs are reported. There are clearly very strong connections with SDGs 3 and 11, as well as 13 (with clear implications on pollution levels) and When it comes to COVID-19 studies, we evaluated the journals with a minimum of ten publications from a total of 1370 journal sources that Indian authors had published. This resulted in 97 items divided into seven clusters, as shown in Figure 5 (bottom). As expected, most of the highly cited papers appeared in high-impact factor journals indicating their higher research quality. Most publishers followed an accelerated review process, onlinefirst policy and provided open access to such publications.

COVID-19 Studies Connected to Sustainable Development
We also evaluated the connections between COVID-19 studies and sustainable development. In this regard, we used 17 United Nations Sustainable Development Goals (SDG), adopted in 2015, as a proxy for sustainable development. The COVID-19 pandemic has had an important impact across all the SDGs, for instance through reduced CO 2 emissions because of the lockdowns [54], with clear implications on SDG 13 (on climate action). However, a number of studies [55,56] suggest that the situation may progressively return to the pre-pandemic levels, in the context instance of aviation and its impact on the environment. Several studies suggest that the symptoms associated with COVID-19 may be exacerbated due to increasing pollution levels [57], a fact that closely connects SDGs 3 (on health) and 11 (on sustainable cities). Another important aspect regarding the management of the COVID-19 has to do with the digital-contact-tracing apps, which aimed at achieving better control of the pandemic, with a positive impact on SDG 3, but could potentially exhibit challenges [58][59][60] in the context of SDGs 10 (on reduced inequalities) and 16 (on strong institutions). The connections reported above have a clear relation with the results presented in Table 9, where the number of Indian COVID-19 articles and their citations related to each of the 17 SDGs are reported. There are clearly very strong connections with SDGs 3 and 11, as well as 13 (with clear implications on pollution levels) and 16. When it comes to the latter, we would like to highlight the strong polarization in our societies, exacerbated by the algorithms used by news outlets and social media [61]; the problems associated with this polarization have become particularly dire due to the COVID-19 pandemic, creating a data crisis [62]. It is also important to note the significant number of studies documenting connections between COVID-19 and SDGs 8 (on economic growth) and 4 (on quality education), which reflect the negative impact of the COVID-19 restrictions on two very important areas of our societies. Perhaps two areas that have not received sufficient attention according to Table 9 are the negative effects on SDGs 1 (on no poverty) and 5 (on gender equality), which have undoubtedly experienced quite negative effects from COVID-19.

Conclusions
In the present study, the authors performed a bibliometric analysis on COVID-19 publications in India and at multiple places compared to the worldwide data. The United States is the country with the highest number of COVID-19 publications in the year 2020. This might reflect the fact that journal databases and the referencing system usually refer to US standards. Many journals, with a wide range of impact factors, exhibit publications by Indian authors. The publications are the result of collaboration both within India and on the international scene. Our results indicate that the studies on COVID-19 are published by institutions worldwide as also reported by [63], who studied bibliometric features on the COVID-19 globally. There are many publications in India, which had a rapidly increasing rate of publication after disease emerged in the country, in a pattern similar to that reported by [64]. This study also shows that there are many publications from both governmental and non-governmental institutes. A worldwide collaboration network can be clearly identified, and this agrees with the report by [65]. Collaboration is an excellent way to increase the visibility of the work and the generalization of the knowledge. During the early stage of disease emergence, studies in the form of short reports or viewpoints were common and become publications with high numbers of citations [66]. Such collaboration and active data-sharing policies are essential aspects to fight this pandemic and other future crises [67][68][69]. The high number of studies on COVID-19 indicates that it will be necessary to conduct active research with the emergence of new variants of the diseases [70][71][72].
We also identified important connections between COVID-19 studies at the 17 SDGs of the UN. In particular, there are clear implications on SDGs 3 (on health), 11 (on sustainable cities), and 13 (on climate action), the two latter due to the reduced emissions following the COVID-19 restrictions. Digital contact tracing must be conducted in a decentralized way in order to avoid negative effects on SDGs 10 (on reduced inequalities) and 16 (on strong institutions). Despite the obvious negative effects of COVID-19 on SDGs 8 (on economic growth) and 4 (on quality education), we would like to highlight the very important consequences of SDGs 1 (on no poverty) and 5 (on gender equality), which are not as prominently represented in the literature.
A detailed assessment of the scientific work published in reaction to the three most notable coronavirus outbreaks, namely SARS, MERS, and COVID-19, reveals striking parallelisms. Public-health and emergency-management studies are the first to appear, followed by virology studies. The volume and rate of scholarly study on COVID-19, on the other hand, remains an outlier, potentially unparalleled in the history of scientific literature.
Although India had a reasonably large number of reported COVID-19 cases, the number of publications at the time of the study still follow countries where the disease occurred earlier. However, in recent weeks, the situation has abruptly changed for the worse with India reporting a very high number of daily cases mainly attributed to the double-mutant strain. Many states have again implemented lockdowns resulting in the closure of campuses. It remains to be seen how the academic community will adapt to this new situation.
In comparison to earlier epidemic outbreaks, the publication of COVID-19 research is moving at a torrid pace. As of 23 June 2021, over 195,568 COVID-19 studies have been published in Scopus. Additionally, there are several tens and thousands in the preprint servers which are not yet peer reviewed. A similar pace is seen with Indian authors who have already published 5403 articles in the first five months of 2021, compared to 6423 articles for all of 2020. It is very possible that bibliometrics as a field is not equipped to explain such steep trajectories of publications and citations in such a short time since bibliometricians work on substantially longer timescales [28,36]. Secondly, unlike the boxed search phrases above, the description of an emerging research area is rarely as clear and understandable.