Text and Data Mining valid from 2017-08-31
Received: 10 December 2016
Accepted: 14 August 2017
First Online: 31 August 2017
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: This article does not contain any studies with human participants or animals performed by any of the authors.
: Informed consent was obtained from all individual participants included in the study.