| article html file updated | 8 February 2020 18:59 CET | Update | https://www.mdpi.com/2075-471X/6/4/21 |
| article html file updated | 2 May 2019 20:03 CEST | Update | - |
| article html file updated | 20 October 2017 12:10 CEST | Original file | - |
| article xml uploaded. | 20 October 2017 12:09 CEST | Original file | https://www.mdpi.com/2075-471X/6/4/21/xml |
| article pdf uploaded. | 20 October 2017 12:09 CEST | Version of Record | https://www.mdpi.com/2075-471X/6/4/21/pdf |
