| article html file updated | 7 February 2020 20:41 CET | Update | https://www.mdpi.com/2073-4395/7/1/4 |
| article html file updated | 22 September 2019 17:22 CEST | Update | - |
| article html file updated | 4 May 2019 16:59 CEST | Update | - |
| article html file updated | 27 March 2017 09:40 CEST | Update | - |
| article html file updated | 3 January 2017 08:31 CET | Original file | - |
| article xml uploaded. | 3 January 2017 08:30 CET | Original file | https://www.mdpi.com/2073-4395/7/1/4/xml |
| article pdf uploaded. | 3 January 2017 08:30 CET | Version of Record | https://www.mdpi.com/2073-4395/7/1/4/pdf |
