Text and Data Mining valid from 2018-04-27
Received: 9 January 2018
Accepted: 5 April 2018
First Online: 27 April 2018
Change Date: 24 July 2018
Change Type: Correction
Change Details: A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.
: The authors declare no competing interests.