Bronger, Holger
Singer, Judith
Windmüller, Claudia
Reuning, Ute
Zech, Daniela
Delbridge, Claire
Dorn, Julia
Kiechle, Marion
Schmalfeldt, Barbara
Schmitt, Manfred
Avril, Stefanie
Article History
Revised: 18 April 2016
Accepted: 11 May 2016
First Online: 4 August 2016
Competing interests
: The authors declare no conflict of interest.