Text and Data Mining valid from 2019-08-16
Received: 18 February 2019
Revised: 21 May 2019
Accepted: 22 May 2019
First Online: 16 August 2019
Change Date: 30 September 2019
Change Type: Update
Change Date: 1 October 2019
Change Type: Correction
Change Details: The original HTML version of this Article was updated after publication to include the Supplementary file, as it was previously omitted.
Change Details: An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Compliance with ethical standards
: The authors declare that they have no conflict of interest.