Funding for this research was provided by:
National Research Foundation (BD0100001)
Text and Data Mining valid from 2019-01-29
Received: 21 August 2018
Accepted: 14 January 2019
First Online: 29 January 2019
Ethics approval and consent to participate
: Not applicable.
: The author’s declare that there have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.