Mushi, E.Z.; Binta, M.G.; Chabo, R.G.; Mathaio, M.; Ndebele, R.T.(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1999)
Botha, C.J. (Christoffel Jacobus); Schultz, R.A. (Rowena Anitra); Van der Lugt, Jaco J.; Retief, E.; Labuschagne, Leonie(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1999)