| article html file updated | 6 February 2020 05:59 CET | Update | https://www.mdpi.com/2223-7747/2/4/769 |
| article html file updated | 7 May 2019 21:15 CEST | Update | - |
| article html file updated | 21 March 2019 08:52 CET | Update | - |
| article html file updated | 19 August 2015 12:23 CEST | Original file | - |
| article pdf uploaded. | 5 December 2013 10:02 CET | Version of Record | https://www.mdpi.com/2223-7747/2/4/769/pdf |
