| article html file updated | 7 February 2020 18:45 CET | Update | https://www.mdpi.com/2078-1547/7/2/21 |
| article html file updated | 4 May 2019 21:03 CEST | Update | N/A |
| article html file updated | 29 November 2016 10:28 CET | Original file | N/A |
| article xml uploaded. | 29 November 2016 10:27 CET | Original file | https://www.mdpi.com/2078-1547/7/2/21/xml |
| article pdf uploaded. | 29 November 2016 10:27 CET | Version of Record | https://www.mdpi.com/2078-1547/7/2/21/pdf |
