| article html file updated | 5 February 2020 21:27 CET | Update | https://www.mdpi.com/2077-0375/2/3/553 | 
| article html file updated | 8 May 2019 15:54 CEST | Update | - | 
| article html file updated | 25 March 2019 13:19 CET | Update | - | 
| article html file updated | 17 June 2015 01:30 CEST | Update | - | 
| article html file updated | 5 March 2015 11:20 CET | Update | - | 
| article xml file uploaded | 5 March 2015 11:20 CET | Update | https://www.mdpi.com/2077-0375/2/3/553/xml | 
| article html file updated | 18 March 2014 09:50 CET | Update | - | 
| article xml file uploaded | 18 March 2014 09:50 CET | Original file | - | 
| article html file updated | 7 February 2013 14:07 CET | Update | - | 
| article html file updated | 7 February 2013 05:12 CET | Update | - | 
| article html file updated | 6 February 2013 09:27 CET | Update | - | 
| article html file updated | 29 January 2013 05:46 CET | Update | - | 
| article html file updated | 26 January 2013 21:01 CET | Update | - | 
| article html file updated | 23 January 2013 23:27 CET | Original file | - |