| article html file updated | 7 February 2020 22:08 CET | Update | https://www.mdpi.com/2227-7102/7/1/21 |
| article html file updated | 4 May 2019 13:47 CEST | Update | - |
| article html file updated | 27 October 2017 09:55 CEST | Update | - |
| article html file updated | 24 January 2017 10:17 CET | Original file | - |
| article xml uploaded. | 24 January 2017 10:15 CET | Original file | https://www.mdpi.com/2227-7102/7/1/21/xml |
| article pdf uploaded. | 24 January 2017 10:15 CET | Version of Record | https://www.mdpi.com/2227-7102/7/1/21/pdf |
