Text and Data Mining valid from 2019-04-27
First Online: 27 April 2019
Change Date: 17 June 2019
Change Type: Correction
Change Details: On page 8, in the left-hand column, third paragraph, lines 9–13 which previously read:
Compliance with Ethical Standards
: No financial support was received for the preparation of this manuscript.
: Nicholas B. Tiller declares that he has no conflicts of interest.