| article html file updated | 7 February 2020 03:42 CET | Update | https://www.mdpi.com/2073-8994/8/1/6 |
| article html file updated | 6 May 2019 02:03 CEST | Update | - |
| article html file updated | 26 March 2019 18:59 CET | Original file | - |
| article pdf uploaded. | 21 January 2016 09:14 CET | Version of Record | https://www.mdpi.com/2073-8994/8/1/6/pdf |
| article xml uploaded. | 21 January 2016 09:14 CET | Original file | https://www.mdpi.com/2073-8994/8/1/6/xml |
