Article History
Received: 27 March 2019
Accepted: 1 October 2019
First Online: 8 October 2019
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: All participants provided their written informed consent after they were briefed about the research protocol which complied with the principles of the Declaration of Helsinki and was approved by Ethical Commission of the Faculty of Social and Behavioral Sciences, Friedrich Schiller University of Jena (No. FSV 18/11).