Article History
Received: 10 July 2019
Accepted: 19 October 2019
First Online: 31 October 2019
Compliance with ethical standards
:
: Eva-Maria Kahle, Martin Zarnkow and Fritz Jacob declare that they have no conflict of interest.
: The authors Eva-Maria Kahle, Martin Zarnkow and Fritz Jacob hereby confirm that this manuscript was prepared according to and follows the COPE guidelines and has not already been published nor is it under consideration for publication elsewhere. This article does not contain any studies with human or animal subjects.