| article html file updated | 6 February 2020 00:08 CET | Update | https://www.mdpi.com/1996-1073/6/1/539 |
| article html file updated | 8 May 2019 09:30 CEST | Update | N/A |
| article html file updated | 20 March 2019 17:33 CET | Update | N/A |
| article html file updated | 14 February 2017 11:28 CET | Original file | N/A |
| article pdf uploaded. | 21 January 2013 13:57 CET | Version of Record | https://www.mdpi.com/1996-1073/6/1/539/pdf |
