Text and Data Mining valid from 2019-01-18
Received: 5 September 2018
Revised: 20 December 2018
Accepted: 24 December 2018
First Online: 18 January 2019
Change Date: 18 September 2019
Change Type: Correction
Change Details: An amendment to this paper has been published and can be accessed via a link at the top of the paper.
: The authors declare no competing interests.