| article html file updated | 6 February 2020 03:14 CET | Update | https://www.mdpi.com/1996-1073/6/7/3506 |
| article html file updated | 8 May 2019 02:50 CEST | Update | N/A |
| article html file updated | 21 March 2019 01:21 CET | Update | N/A |
| article html file updated | 30 March 2017 11:55 CEST | Original file | N/A |
| article pdf uploaded. | 16 July 2013 14:53 CEST | Version of Record | https://www.mdpi.com/1996-1073/6/7/3506/pdf |
