Text and Data Mining valid from 2019-01-21
Received: 22 October 2018
Accepted: 9 January 2019
First Online: 21 January 2019
Ethics approval and consent to participate
: The study was approved by the Ethics committee of the University of Münster (protocol number 2014–544-f-S) on 6 November 2014 and all students gave written informed consent to participate.
: Not applicable.
: The authors declare that they have no competing interests.
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