Text and Data Mining valid from 2019-02-07
Received: 25 January 2019
Accepted: 4 February 2019
First Online: 7 February 2019
Compliance with ethical standards
: None of the authors have conflict of interests.
: This article is a review of the literature and does not contain any studies with human participants or animals performed by any of the authors.
: No informed consent is available.