Text and Data Mining valid from 2016-12-19
Received: 13 July 2016
Accepted: 20 October 2016
First Online: 19 December 2016
Change Date: 14 July 2017
Change Type: Erratum
Change Details: In the PDF version of this article previously published, the year of publication provided in the footer of each page and in the 'How to cite' section was erroneously given as 2017, it should have been 2016. This error has now been corrected. The HTML version of the article was not affected.
: The authors declare no competing financial interests.