Lotriet, H.H. (Hugo H.); Matthee, Machdel C.; Mazanderani, Fadhila(Department of Knowledge and Information Management, University of Johannesburg, 2009-03)
Kroeze, J.H. (Jan Hendrik); Bothma, T.J.D. (Theodorus Jan Daniel); Matthee, Machdel C.(Vaal Triangle Faculty of Northwest University in South Africa, 2010-07)