Funding for this research was provided by:
Text and Data Mining valid from 2019-04-10
Received: 29 November 2018
Accepted: 20 March 2019
First Online: 10 April 2019
Compliance with ethical standards
: All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript.
: For this type of study formal consent is not required. This article does not contain any studies with human participants performed by any of the authors.