Mushi, E.Z.; Binta, M.G.; Chabo, R.G.; Ndebele, R.; Panzirah, R.(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute ., 2000)
Bowles, P.M.; Molloy, J.B.; Blight, G.W.; Singh, S.; Mabikacheche, L.G.(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute ., 2000)