| article html file updated | 6 February 2020 09:48 CET | Update | https://www.mdpi.com/2076-3921/3/2/439 |
| article html file updated | 21 March 2019 18:26 CET | Update | N/A |
| article html file updated | 20 August 2015 09:22 CEST | Original file | N/A |
| article pdf uploaded. | 10 June 2014 10:05 CEST | Version of Record | https://www.mdpi.com/2076-3921/3/2/439/pdf |
