| article html file updated | 6 February 2020 04:07 CET | Update | https://www.mdpi.com/1996-1073/6/9/4551 |
| article html file updated | 8 May 2019 00:59 CEST | Update | N/A |
| article html file updated | 21 March 2019 03:57 CET | Update | N/A |
| article html file updated | 13 February 2017 02:33 CET | Original file | N/A |
| article pdf uploaded. | 3 September 2013 17:17 CEST | Updated version of record | https://www.mdpi.com/1996-1073/6/9/4551/pdf |
| article pdf uploaded. | 2 September 2013 14:14 CEST | Version of Record | https://www.mdpi.com/1996-1073/6/9/4551/pdf-vor |
