Funding for this research was provided by:
Baden-Württemberg Stiftung (grant number: BWS_1.479.00_2009)
Received: 26 January 2019
Accepted: 25 April 2019
First Online: 16 May 2019
Ethics approval and consent to participate
: Ethic Committee of Ulm University gave approval and consent on 09.06.2010. The study was registered at the German Clinical Trials Register (DRKS) with the following Number DRKS-ID: DRKS00000494 on 25/08/2010. To participate school’s leadership and teachers had to provide written, informed consent. For data collection of data, parents provided written, informed consent and children their assent.
: Not applicable.
: The authors declare that they have no competing interests.
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