1. Hussein, N. A., Bolbol, A. S., Karam, H. A. & Ganaba, S. M. (1978). Report for Agricultural Research Centre, Socialist People's Libyan Arab Jamahiriya.
2. Ogunsusi, R. A. & Eysker, M. (1979).Research in Veterinary Science,26, 108–110.
3. Pullar, E. M. (1953).Australian Veterinary Journal,29, 357–362.
4. Skerman, K. D. & Hillard, J. J. (1966). Near East Animal Health Institute Handbook No. 2, FAO, Rome.