| article html file updated | 6 February 2020 00:49 CET | Update | https://www.mdpi.com/1996-1073/6/3/1421 |
| article html file updated | 8 May 2019 07:44 CEST | Update | N/A |
| article html file updated | 20 March 2019 19:20 CET | Update | N/A |
| article html file updated | 14 February 2017 11:29 CET | Original file | N/A |
| article pdf uploaded. | 5 March 2013 17:16 CET | Version of Record | https://www.mdpi.com/1996-1073/6/3/1421/pdf |
