Braun, Norbert
Klumpp, Dominik
Hennenlotter, Jörg
Bedke, Jens
Duranton, Christophe
Bleif, Martin
Huber, Stephan M.
Article History
Received: 3 November 2014
Accepted: 1 July 2015
First Online: 25 August 2015
Competing interests
: The authors declare no competing financial interests.