Spickett, Arthur M.; Burger, D.B.; Crause, J.C.; Roux, Elizabeth M.(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1991)
Scholtz, M.M.; Spickett, Arthur M.; Lombard, P.E.; Enslin, C.B.(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1991)