Text and Data Mining valid from 2018-05-24
Received: 26 February 2017
Accepted: 17 May 2018
First Online: 24 May 2018
Ethics approval and consent to participate
: The study was submitted to the Ethics Committee of the Ruhr University of Bochum (Germany) and approved after examination (registry no. 4522-12). The dataset was anonymized prior to analysis.
: The authors declare that they have no competing interests.
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