Text and Data Mining valid from 2019-02-25
Received: 21 June 2018
Accepted: 17 January 2019
First Online: 25 February 2019
Change Date: 26 June 2019
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.