1. Alexander, R. A., Plowright, W. &Haig, D. A. (1957).Bulletin of Epizootic Diseases of Africa,5, 489–492.
2. Ali, B. H. &Obeid, H. M. (1977).British Veterinary Journal,133, 184–189.
3. Anon. (1974).Rapport Animal Laboratoire de Farcha 1973,1, 62.
4. Bida, S. A., Alhaji, I., Eid, F. I. A. &Mustapha, H. B. (1976).Journal of Nigerian Veterinary Medical Association,5, 21–26.
5. FAO-WHO-OIE (1965–74).Animal Health Yearbook.