| article html file updated | 6 February 2020 00:30 CET | Update | https://www.mdpi.com/2073-4336/4/1/50 |
| article html file updated | 8 May 2019 08:33 CEST | Update | - |
| article html file updated | 20 March 2019 18:30 CET | Update | - |
| article html file updated | 19 December 2016 11:37 CET | Original file | - |
| article pdf uploaded. | 7 February 2013 16:50 CET | Version of Record | https://www.mdpi.com/2073-4336/4/1/50/pdf |
