Text and Data Mining valid from 2019-11-21
First Online: 21 November 2019
Compliance with Ethical Standards
: No sources of funding were used to assist in the preparation of this article.
: Renato Mattli, Renato Farcher, Maria-Eleni Syleouni, Simon Wieser, Nicole Probst-Hensch, Arno Schmidt-Trucksäss and Matthias Schwenkglenks declare that they have no conflicts of interest relevant to the content of this review.