Huppert, Doreen
Brandt, Thomas
Funding for this research was provided by:
Bundesministerium für Bildung und Forschung
Gemeinnützige Hertie-Stiftung
Article History
Received: 30 January 2018
Accepted: 21 February 2018
First Online: 12 March 2018
Compliance with ethical standards
:
: The authors declare that they have no competing interests.
: The study was performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki.