| article html file updated | 6 February 2020 15:05 CET | Update | https://www.mdpi.com/1999-4907/6/1/203 |
| article html file updated | 7 May 2019 02:40 CEST | Update | N/A |
| article html file updated | 25 March 2019 20:20 CET | Update | N/A |
| article html file updated | 21 August 2015 05:33 CEST | Original file | N/A |
| article pdf uploaded. | 9 January 2015 14:28 CET | Version of Record | https://www.mdpi.com/1999-4907/6/1/203/pdf |
