Keet, D.F.; Kriek, N.P.J.; Bengis, Roy G.(Published jointly by the Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2001)
Bengis, Roy G.; Keet, D.F.; Kriek, N.P.J.(Published jointly by the Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2001)