Funding for this research was provided by:
Text and Data Mining valid from 2019-08-14
Received: 27 May 2019
Accepted: 26 July 2019
First Online: 14 August 2019
Compliance with ethical standards
: Ethical approval for this work was granted through the Cranfield University Research Ethics System (CURES/3579/2017).
: The authors declare that they have no conflict of interest.