| article html file updated | 6 February 2020 02:14 CET | Update | https://www.mdpi.com/2076-3387/3/2/6 |
| article html file updated | 19 September 2019 21:01 CEST | Update | N/A |
| article html file updated | 8 May 2019 04:54 CEST | Update | N/A |
| article html file updated | 20 March 2019 22:49 CET | Update | N/A |
| article html file updated | 17 June 2015 09:31 CEST | Original file | N/A |
| article pdf uploaded. | 22 May 2013 12:04 CEST | Version of Record | https://www.mdpi.com/2076-3387/3/2/6/pdf |
