| article html file updated | 6 February 2020 14:19 CET | Update | https://www.mdpi.com/2223-7747/3/4/613 |
| article html file updated | 7 May 2019 04:15 CEST | Update | N/A |
| article html file updated | 25 March 2019 18:59 CET | Update | N/A |
| article html file updated | 21 August 2015 03:47 CEST | Original file | N/A |
| article pdf uploaded. | 9 December 2014 13:31 CET | Version of Record | https://www.mdpi.com/2223-7747/3/4/613/pdf |
