Text and Data Mining valid from 2019-08-14
Received: 5 November 2018
Revised: 12 June 2019
Accepted: 18 June 2019
First Online: 14 August 2019
Change Date: 23 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.
Compliance with ethical standards
: The authors declare that they have no conflict of interest.