Funding for this research was provided by:
German Federal Ministry of Education and Research (FKZ 0330800A)
Text and Data Mining valid from 2019-09-09
Received: 26 December 2018
Accepted: 5 September 2019
First Online: 9 September 2019
Compliance with Ethical Standards
: The authors declare no conflict of interest with respect to authorship or publication of this article.