| article html file updated | 8 February 2020 01:33 CET | Update | https://www.mdpi.com/2076-3921/6/1/21 |
| article html file updated | 23 September 2019 20:18 CEST | Update | - |
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| article html file updated | 29 March 2017 08:17 CEST | Update | - |
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| article xml uploaded. | 16 March 2017 07:08 CET | Original file | https://www.mdpi.com/2076-3921/6/1/21/xml |
| article pdf uploaded. | 16 March 2017 07:08 CET | Version of Record | https://www.mdpi.com/2076-3921/6/1/21/pdf |
