Text and Data Mining valid from 2019-04-10
Received: 5 October 2018
Accepted: 25 March 2019
First Online: 10 April 2019
Compliance with ethical guidelines
: L. König, N. Bougatf, J. Hörner-Rieber, N. Chaudhri, T. Mielke, S. Klüter, M.F. Haefner, S. Rieken, T. Haberer, J. Debus and K. Herfarth declare that they have no competing interests.
: 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. Ethical approval was obtained from the local Ethics Committee of Heidelberg University (S-201/2017).