| article html file updated | 7 February 2020 03:57 CET | Update | https://www.mdpi.com/2218-1989/6/1/7 |
| article html file updated | 6 May 2019 01:36 CEST | Update | - |
| article html file updated | 26 March 2019 19:28 CET | Update | - |
| article html file updated | 30 March 2016 07:55 CEST | Original file | - |
| article pdf uploaded. | 27 January 2016 11:17 CET | Version of Record | https://www.mdpi.com/2218-1989/6/1/7/pdf |
| article xml uploaded. | 27 January 2016 11:17 CET | Original file | https://www.mdpi.com/2218-1989/6/1/7/xml |
