Text and Data Mining valid from 2018-08-10
Received: 23 June 2018
Accepted: 23 July 2018
First Online: 10 August 2018
Compliance with Ethical Standards
: The authors declare that they have no conflict of interest.
: All procedures involving human participants were in accordance with the ethical standards of the institution.
: Informed consent was obtained from all individual participants included in the study.