Kowalski, Christoph
Carl, Günther
Feick, Günter
Wesselmann, Simone
Article History
Received: 10 July 2019
Accepted: 13 November 2019
First Online: 16 June 2020
Conflict of interest
: C. Kowalski and S. Wesselmann are employees of the German Cancer Society. G. Carl and G. Feick declare that they have no competing interests.