| article html file updated | 6 February 2020 14:50 CET | Update | https://www.mdpi.com/1999-4907/6/1/47 |
| article html file updated | 7 May 2019 03:12 CEST | Update | N/A |
| article html file updated | 25 March 2019 19:54 CET | Update | N/A |
| article html file updated | 21 August 2015 04:59 CEST | Original file | N/A |
| article pdf uploaded. | 29 December 2014 15:50 CET | Version of Record | https://www.mdpi.com/1999-4907/6/1/47/pdf |
