Text and Data Mining valid from 2018-11-23
Received: 15 August 2018
Accepted: 30 September 2018
First Online: 23 November 2018
Ethics approval and consent to participate
: Ethics approval is not applicable. Informed written consent has been obtained from all participants.
: Not applicable
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.