Kwenani, K.M. (Kingsley Mabuku); Terblanche, S.E. (Stephanus Esaias), 1940-(South African Society for Agricultural Extension, Department of Agriculture, Ecomomics, Extensions and Rural Development, University of Pretoria, 2009)
D'Haese, M.F.C. (Marijke); Calus, M.; Kirsten, Johann F.; Van Huylenbroeck, Guido; Bostyn, F.(Agricultural Economics Association of South Africa, 2001-12)