| article html file updated | 6 February 2020 06:14 CET | Update | https://www.mdpi.com/1996-1073/6/12/6508 |
| article html file updated | 7 May 2019 20:47 CEST | Update | - |
| article html file updated | 21 March 2019 09:32 CET | Update | - |
| article html file updated | 14 February 2017 11:38 CET | Original file | - |
| article pdf uploaded. | 16 December 2013 17:36 CET | Version of Record | https://www.mdpi.com/1996-1073/6/12/6508/pdf |
