Text and Data Mining valid from 2018-09-26
Received: 23 April 2018
Accepted: 5 September 2018
First Online: 26 September 2018
Change Date: 19 October 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 been fixed in the paper.
: The authors declare no competing interests.