,
Vorwieger, Eva
Kelso, Anne
Steinacker, Jürgen Michael
Kesztyüs, Dorothea http://orcid.org/0000-0002-2166-846X
Funding for this research was provided by:
Baden-Württemberg Stiftung
Article History
Received: 24 April 2017
Accepted: 14 February 2018
First Online: 23 February 2018
Ethics approval and consent to participate
: The study protocol was approved by the ethics committee of Ulm University in 2006. Written informed consent was obtained from parents and teachers.
: Not applicable
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.