Text and Data Mining valid from 2019-11-04
Received: 4 June 2019
Accepted: 27 October 2019
First Online: 4 November 2019
Ethics approval and consent to participate
: The study was performed in accordance with national legislation and with the approval of the local ethics committee of the Justus-Liebig-University of Giessen, Germany (Number of compliancy: 600_M/2016).
: Not applicable.
: The authors declare that they have no competing interests.