Text and Data Mining valid from 2018-06-28
First Online: 28 June 2018
Compliance with Ethical Standards
: The author declares that he has no conflict of interest.
: 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.
: This article does not contain any studies with animals performed by any of the authors.
: Informed consent was obtained from all individual participants included in the study.