| article html file updated | 6 February 2020 06:02 CET | Update | https://www.mdpi.com/2227-9040/1/3/68 |
| article html file updated | 7 May 2019 21:10 CEST | Update | N/A |
| article html file updated | 21 March 2019 08:58 CET | Update | N/A |
| article html file updated | 19 August 2015 12:49 CEST | Original file | N/A |
| article pdf uploaded. | 9 December 2013 14:23 CET | Updated version of record | https://www.mdpi.com/2227-9040/1/3/68/pdf |
| article pdf uploaded. | 6 December 2013 16:35 CET | Version of Record | https://www.mdpi.com/2227-9040/1/3/68/pdf-vor |
