Text and Data Mining valid from 2017-02-06
Received: 8 July 2016
Accepted: 24 January 2017
First Online: 6 February 2017
Compliance with Ethical Standards
: There are no potential conflicts of interests.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institution.
: Informed consent was obtained from all individual participants in the study (from parents as the child is 4 years old).