Wiese, Melanie; Van Heerden, Cornelius Hendrik, 1957-; Van Heerden, Neels, 1957-; Jordaan, Yolanda(University of Johannesburg, Department of Business Management, 2010)
Douglas, Anneli; Mostert, P.G. (Pierre); Slabbert, Liandi Magdalena(Department of Recreation, Park, and Tourism Sciences at Texas AandM University, 2019)