Terblanche, S.E. (Stephanus Esaias), 1940-(South African Society for Agricultural Extension, Department of Agriculture, Ecomomics, Extensions and Rural Development, University of Pretoria, 2008)
Zwane, E.M.; Duvel, G.H. (Gustav Heinrich)(South African Society for Agricultural Extension, Department of Agriculture, Ecomomics, Extensions and Rural Development, University of Pretoria, 2008)
Du Plessis, Willemien (Wilhelmina), 1958-; Pienaar, Juanita (Juanita Magrietha), 1965-; Olivier, N.J.J. (Nicolaas Johannes Jacobus)(The Verloren van Themaat Centre for Public Law Studies,UNISA, 2008)