Text and Data Mining valid from 2018-04-09
Received: 31 May 2017
Revised: 18 September 2017
Accepted: 20 September 2017
First Online: 9 April 2018
Change Date: 24 May 2018
Change Type: Correction
Change Details: One of the author names was misspelled. This has now been corrected in the HTML and PDF versions of this article.
: The authors declare no competing interests.