| article html file updated | 6 February 2020 02:46 CET | Update | https://www.mdpi.com/2227-7072/1/2/32 |
| article html file updated | 8 May 2019 03:46 CEST | Update | - |
| article html file updated | 21 March 2019 00:09 CET | Update | - |
| article html file updated | 17 June 2015 10:27 CEST | Original file | - |
| article pdf uploaded. | 21 June 2013 13:27 CEST | Version of Record | https://www.mdpi.com/2227-7072/1/2/32/pdf |
