| article html file updated | 6 February 2020 06:27 CET | Update | https://www.mdpi.com/2227-7102/4/1/13 |
| article html file updated | 7 May 2019 20:22 CEST | Update | N/A |
| article html file updated | 21 March 2019 10:11 CET | Update | N/A |
| article html file updated | 19 August 2015 15:39 CEST | Original file | N/A |
| article pdf uploaded. | 27 December 2013 16:47 CET | Version of Record | https://www.mdpi.com/2227-7102/4/1/13/pdf |
