| article html file updated | 6 February 2020 00:57 CET | Update | https://www.mdpi.com/2227-7102/3/1/50 |
| article html file updated | 8 May 2019 07:29 CEST | Update | - |
| article html file updated | 20 March 2019 19:40 CET | Update | - |
| article html file updated | 17 June 2015 07:23 CEST | Original file | - |
| article pdf uploaded. | 11 March 2013 16:40 CET | Version of Record | https://www.mdpi.com/2227-7102/3/1/50/pdf |
