Funding for this research was provided by:
RWTH Aachen University (StUpPD 262-17.)
Deutsche Forschungsgemeinschaft (research grant SCHM 2643/13-1)
Text and Data Mining valid from 2018-12-01
Received: 6 September 2018
Accepted: 16 November 2018
First Online: 6 December 2018
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.