Funding for this research was provided by:
Bundesministerium für Bildung und Forschung (031B0342A)
Text and Data Mining valid from 2019-01-29
Received: 27 November 2018
Revised: 3 January 2019
Accepted: 4 January 2019
First Online: 29 January 2019
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: This article does not contain any studies with human participants or animals performed by any of the authors.