| article html file updated | 6 February 2020 15:42 CET | Update | https://www.mdpi.com/2076-0787/4/1/68 |
| article html file updated | 20 September 2019 17:38 CEST | Update | N/A |
| article html file updated | 7 May 2019 01:28 CEST | Update | N/A |
| article html file updated | 25 March 2019 21:20 CET | Original file | N/A |
| article pdf uploaded. | 4 February 2015 09:00 CET | Version of Record | https://www.mdpi.com/2076-0787/4/1/68/pdf |
