Emslie, Forbes Richard; Spickett, Arthur M.(Published jointly by the Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2001)
Zandbergen, Thijs A.; Van de Wiel, Paul A.; De Groot, Mia; Uilenberg, Gerrit(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1991)