| article html file updated | 7 February 2020 06:20 CET | Update | https://www.mdpi.com/2226-4310/3/2/9 |
| article html file updated | 5 May 2019 20:35 CEST | Update | N/A |
| article html file updated | 27 March 2019 00:12 CET | Update | N/A |
| article html file updated | 27 June 2016 12:04 CEST | Original file | N/A |
| article pdf uploaded. | 24 March 2016 10:32 CET | Version of Record | https://www.mdpi.com/2226-4310/3/2/9/pdf |
