| article html file updated | 7 February 2020 02:36 CET | Update | https://www.mdpi.com/1996-1073/9/1/4 |
| article html file updated | 6 May 2019 04:13 CEST | Update | - |
| article html file updated | 26 March 2019 17:05 CET | Original file | - |
| article pdf uploaded. | 24 December 2015 11:16 CET | Updated version of record | https://www.mdpi.com/1996-1073/9/1/4/pdf |
| article pdf uploaded. | 23 December 2015 13:12 CET | Version of Record | https://www.mdpi.com/1996-1073/9/1/4/pdf-vor |
| article xml uploaded. | 23 December 2015 13:12 CET | Original file | https://www.mdpi.com/1996-1073/9/1/4/xml |
