Funding for this research was provided by:
National Science Foundation (Soc. 75 l4227, BCS 1122932, NSF Soc. 75 02253, BNS 76-19633)
Brot fur die Welt ((Project No. 2013 0148 G)
Text and Data Mining valid from 2019-02-14
First Online: 14 February 2019
Compliance with Ethical Standards
: The authors declare that they have no conflicts of interest.