Funding for this research was provided by:
Bundesministerium für Wirtschaftliche Zusammenarbeit und Entwicklung (11.7860.7-001.00)
Text and Data Mining valid from 2019-01-06
Received: 11 January 2018
Accepted: 27 December 2018
First Online: 6 January 2019
Compliance with ethical standards
: The authors declare that they have no conflict of interest.