Text and Data Mining valid from 2017-07-07
First Online: 7 July 2017
Compliance with Ethical Standards
: Authors declare no conflict of interests.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Informed consent was obtained from all individual participants included in the study.