Funding for this research was provided by:
Hungarian National Research, Development and Innovation Office (K111938, KKP126835)
Text and Data Mining valid from 2018-04-11
First Online: 11 April 2018
Compliance with Ethical Standards
: The study was approved by the first author’s university ethics committee and was carried out in accordance with the 1975 Helsinki declaration. All of the participants have given their informed consent and participated in the study voluntarily and anonymously.
: All the authors declare that they have no conflict of interest.