Stevens, K.B.; Spickett, Arthur M.; Vosloo, Wilna; Pfeiffer, Dirk U.; Dyason, Edwin; Du Plessis, B.(Agricultural Research Council, ARC-OVI and the University of Pretoria, 2007-06)
Niemann-Struweg, Ilse; Meintjes, Corne; Grobler, Anske F.(Unit for Community Communication, Dept of Communication and Information Studies, University of the Free State, 2007)
Hattingh, Annemarie; Van Loggerenberg-Hattingh, Annemarie; Aldous, Colleen; Rogan, John M.(Southern African Association for Research in Mathematics, Science and Technology Education, 2007)