1. Constraints to lamb survival;Alexander,1984
2. Genetic parameters for lamb birth weight in spring and autumn lambing;Al-Shorepy;Anim. Sci.,1998
3. Autumn and winter lambing strategies in Northland;Andrewes;Proc. N. Z. Grassland Assoc.,1986
4. Patterns of Mammalian Reproduction;Asdell,1964
5. Report of the Committee to Consider the Ethical Implications of Emerging Technologies in the Breeding of Farm Animals;Banner,1995