Harvey W R. 1977. Users' guide for least-squares and maximum likelihood computer program. Ohio State University, Columbus.
Kiwuwa G H. Trail J C M, Kurtu M Y. Getachew Worku, Anderson F M and Durkin J. 1983. Crossbred dairy productivity in Arsi Region, Ethiopia. ILCA Research Report 11. Addis Ababa.
McDowell R E and Schermerhorn E C. 1978. Planning breed improvement programs for dairying in tropical areas. In: Proceedings of the Third Regional Livestock Meeting, Dairy Cattle Production. Kingston, Jamaica. (Cited in McDowell, 1983).
McDowell R E. 1983. Strategy for improving beef and dairy cattle in the tropics. Cornell International Agriculture Mimeo 100.
