| article html file updated | 7 February 2020 10:35 CET | Update | https://www.mdpi.com/2221-3759/4/2/21 |
| article html file updated | 5 May 2019 12:09 CEST | Update | - |
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| article html file updated | 1 July 2016 11:46 CEST | Update | - |
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| article xml uploaded. | 22 June 2016 11:38 CEST | Original file | https://www.mdpi.com/2221-3759/4/2/21/xml |
| article pdf uploaded. | 22 June 2016 11:38 CEST | Version of Record | https://www.mdpi.com/2221-3759/4/2/21/pdf |
