Swan, Gerry E.; Oliver, D.W.; Van Rensburg, J.; Steyn, H.S.; Mulders, M.S.G.(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute ., 2000)
Mbati, P.A.; Hirumi, K.; Inoue, N.; Situakibanza, N.H.; Hirumi, H.(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute ., 2000)