| article html file updated | 7 February 2020 02:33 CET | Update | https://www.mdpi.com/1420-3049/21/1/4 |
| article html file updated | 6 May 2019 04:20 CEST | Update | N/A |
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| article pdf uploaded. | 22 December 2015 18:57 CET | Updated version of record | https://www.mdpi.com/1420-3049/21/1/4/pdf |
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| article xml uploaded. | 22 December 2015 12:54 CET | Original file | https://www.mdpi.com/1420-3049/21/1/4/xml |