| article html file updated | 6 February 2020 01:43 CET | Update | https://www.mdpi.com/2223-7747/2/2/248 |
| article html file updated | 8 May 2019 05:53 CEST | Update | N/A |
| article html file updated | 20 March 2019 21:35 CET | Update | N/A |
| article html file updated | 17 June 2015 08:44 CEST | Original file | N/A |
| article pdf uploaded. | 24 April 2013 15:05 CEST | Version of Record | https://www.mdpi.com/2223-7747/2/2/248/pdf |
