| article html file updated | 7 February 2020 15:55 CET | Update | https://www.mdpi.com/2076-328X/6/4/21 |
| article html file updated | 22 September 2019 02:12 CEST | Update | N/A |
| article html file updated | 5 May 2019 02:25 CEST | Update | N/A |
| article html file updated | 29 December 2016 06:07 CET | Update | N/A |
| article html file updated | 2 October 2016 07:40 CEST | Original file | N/A |
| article xml uploaded. | 2 October 2016 07:39 CEST | Original file | https://www.mdpi.com/2076-328X/6/4/21/xml |
| article pdf uploaded. | 2 October 2016 07:39 CEST | Version of Record | https://www.mdpi.com/2076-328X/6/4/21/pdf |
