1. Barnett, S.F. (1968) In, Infectious Blood Diseases of Man and Animals (Weinmann, D. & Ristic, M. eds.) Vol. II, p. 269, Academic Press, London.
2. Ilemobade, A.A. (1976) Ph.D. Thesis. Ahmadu Bello University, Zaria.
3. Irvin, A.D., Brown, C.G.D., Burridge, M.J., Cunningham, M.P., Musoke, A.J., Peirce, M.A., Purneil, R.E. & Radley, D.E. (1972) Trop. Anim. Hlth Prod. 4, 220.
4. Purnell, R.E. (1977) Adv. Parasit. 15, 83.
5. Uilenberg, G. (1971) Rev. Elev. Med. vet. Pays Trop. 24, 23.