| article html file updated | 6 February 2020 07:31 CET | Update | https://www.mdpi.com/1999-4893/7/1/60 |
| article html file updated | 7 May 2019 18:08 CEST | Update | - |
| article html file updated | 21 March 2019 12:57 CET | Update | - |
| article html file updated | 13 February 2017 02:26 CET | Original file | - |
| article pdf uploaded. | 25 February 2014 14:18 CET | Version of Record | https://www.mdpi.com/1999-4893/7/1/60/pdf |
