| article html file updated | 7 February 2020 21:06 CET | Update | https://www.mdpi.com/2075-1729/7/1/4 |
| article html file updated | 4 May 2019 16:07 CEST | Update | N/A |
| article html file updated | 29 March 2017 07:45 CEST | Update | N/A |
| article html file updated | 11 January 2017 12:54 CET | Original file | N/A |
| article pdf uploaded. | 10 January 2017 14:28 CET | Version of Record | https://www.mdpi.com/2075-1729/7/1/4/pdf |
