Schlesinger, Torsten
Löbig, Anna
Ehnold, Peter
Nagel, Siegfried
Funding for this research was provided by:
Deutscher Fußball Bund
Article History
Received: 1 December 2017
Accepted: 20 March 2018
First Online: 23 April 2018
Compliance with ethical guidelines
:
: T. Schlesinger, A. Löbig, P. Ehnold and S. Nagel declare that they have no competing interests.
: This article does not contain any studies with human participants or animals performed by any of the authors.