Text and Data Mining valid from 2019-08-13
First Online: 13 August 2019
Compliance with Ethical Standards
: Anwar A. Alghamdi gratefully acknowledges the King Abdulaziz University for funding his PhD programme at the University of Manchester. No sources of funding were received for the conduct of this systematic review or preparation of this article.
: Anwar A. Alghamdi, Richard N. Keers, Adam Sutherland and Darren M. Ashcroft have no conflicts of interest that are directly relevant to the content of this article.
: This research does not contain any studies with human participants or animals performed by any of the authors.