Michen, Benjamin
Geers, Christoph
Vanhecke, Dimitri
Endes, Carola
Rothen-Rutishauser, Barbara
Balog, Sandor
Petri-Fink, Alke
Article History
Received: 9 January 2015
Accepted: 19 March 2015
First Online: 12 May 2015
Competing interests
: The authors declare no competing financial interests.