Ponce-Salvatierra, Almudena
Wawrzyniak-Turek, Katarzyna
Steuerwald, Ulrich
Höbartner, Claudia
Pena, Vladimir
Article History
Received: 24 July 2015
Accepted: 20 November 2015
First Online: 6 January 2016
Competing interests
: The authors declare no competing financial interests.