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, 2013)
Pienaar, Juanita (Juanita Magrietha), 1965-; Olivier, N.J.J. (Nicolaas Johannes Jacobus); Du Plessis, Willemien (Wilhelmina), 1958-(The Verloren van Themaat Centre for Public Law Studies, UNISA, 2011)
Terblanche, S.E. (Stephanus Esaias), 1940-(South African Society for Agricultural Extension, Department of Agriculture, Ecomomics, Extensions and Rural Development, University of Pretoria, 2013)
Pienaar, Juanita (Juanita Magrietha), 1965-; Olivier, N.J.J. (Nicolaas Johannes Jacobus)(The Verloren van Themaat Centre for Public Law Studies, UNISA, 2009)
Masuku, Micah Bheki; Kirsten, Johann F.; Van Rooyen, C.J. (Cornelius Johannes); Perret, S. (Sylvain)(Agricultural Economics Association of South Africa, 2003-09)