Text and Data Mining valid from 2018-05-23
Received: 8 April 2018
Accepted: 1 May 2018
First Online: 23 May 2018
Change Date: 25 May 2018
Change Type: Update
Change Details: This Article was updated shortly after publication following a technical error which resulted in single characters throughout the text being replaced by periods. These errors have been corrected in both the HTML and PDF versions of the Article.
: The authors declare no competing interests.