De Lisle, G.W.; Collins, D.M.; Huchzermeyer, Hildegard F.A.K.(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1992)
Gabriel, Sarah; Phiri, I.K.; Dorny, P.; Vercruysse, J.(Published jointly by the Agricultural Research Council, ARC-Onderstepoort Veterinary Institute and the Faculty of Veterinary Science, University of Pretoria., 2001)