Text and Data Mining valid from 2018-09-20
Received: 25 May 2017
Accepted: 17 September 2018
First Online: 20 September 2018
Compliance with Ethical Standards
: Authors declare that there are no known conflicts of interest.
: The study was approved by the Ethics Committee of the North-West University, Potchefstroom with reference number NWU-00125-11-A1.
: Informed consent was obtained from all individual participants. Participants were reimbursed for transportation.