Text and Data Mining valid from 2018-03-09
Received: 21 November 2017
Accepted: 30 January 2018
First Online: 9 March 2018
Change Date: 1 June 2018
Change Type: Correction
Change Details: The original version of this Article had an incorrect Received date of 21 November 2016; it should have been 21 November 2017. This has been corrected in the PDF and HTML versions of the Article.
: The authors declare no competing financial interests.