Text and Data Mining valid from 2018-03-09
Received: 17 November 2017
Accepted: 20 February 2018
First Online: 9 March 2018
Change Date: 3 August 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.