Bastianello, Stella S.; Fourie, Niel; Nel, P.W.; Kellerman, T. Stephanus(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1995)
Fourie, Niel; Bastianello, Stella S.; Nel, P.W.; Kellerman, T. Stephanus(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1991)