| article html file updated | 7 February 2020 05:34 CET | Update | https://www.mdpi.com/2076-3271/4/1/4 |
| article html file updated | 5 May 2019 22:11 CEST | Update | - |
| article html file updated | 26 March 2019 22:48 CET | Original file | - |
| article pdf uploaded. | 8 March 2016 11:51 CET | Version of Record | https://www.mdpi.com/2076-3271/4/1/4/pdf |
| article xml uploaded. | 8 March 2016 11:51 CET | Original file | https://www.mdpi.com/2076-3271/4/1/4/xml |
