| article pdf uploaded. | 13 January 2020 08:44 CET | Updated version of record | https://www.mdpi.com/2504-3900/9/1/63/pdf |
| article xml file uploaded | 13 January 2020 08:44 CET | Original file | - |
| article pdf uploaded. | 18 July 2019 07:24 CEST | Version of Record | https://www.mdpi.com/2504-3900/9/1/63/pdf-vor |
