Hammer, Veronika
Hammer, Katharina
Memaran, Nima
Huber, Wolf-Dietrich
Hammer, Karin
Hammer, Johann http://orcid.org/0000-0002-2452-1201
Article History
Received: 11 December 2017
Accepted: 22 February 2018
First Online: 7 March 2018
Change Date: 2 April 2018
Change Type: Correction
Change Details: The original version of this article unfortunately contained an error in a couple of reference citation in Discussion Section, paragraph 6. The reference citation number should be changed from [6] to [9] in the below sentences so that it reads.
Compliance with ethical standards
:
: No conflicts of interest exist.
: For studies without financial support from industrial sponsors, we provide the questionnaires free of charge.