Schneider, D.J.; Miles, Christopher O.; Garthwaite, I.; Van Halderen, A.; Wessels, J.C.; Lategan, H.J.(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1996)
Bezuidenhout, A.J. (Abraham Johannes), 1942-; Seegers, Christine D.(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1996)