Van der Merwe, N.J.; Bezuidenhout, A.J. (Abraham Johannes), 1942-; Seegers, Christine D.(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1995)
Van Rensburg, I.B.J.; Jardine, J.E.; Carstens, J.H.; Van der Walt, M.L.(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1995)