Funding for this research was provided by:
Academy of Finland (320162)
Text and Data Mining valid from 2019-11-15
Received: 22 August 2019
Accepted: 29 October 2019
First Online: 15 November 2019
Compliance with Ethical Standards
: The authors declare that they have no conflict of interest.
: The research was conducted in compliance with the ethical standards laid down in the 1964. Declaration of Helsinki and its later amendments, and in compliance with the ethical standards and guidelines in Finland.
: Informed consent was obtained from all individual participants included in the study and their parents.