| article html file updated | 6 February 2020 03:27 CET | Update | https://www.mdpi.com/2221-3759/1/2/126 |
| article html file updated | 8 May 2019 02:24 CEST | Update | - |
| article html file updated | 21 March 2019 02:01 CET | Update | - |
| article html file updated | 17 June 2015 11:47 CEST | Original file | - |
| article pdf uploaded. | 26 July 2013 11:09 CEST | Version of Record | https://www.mdpi.com/2221-3759/1/2/126/pdf |
