1. ARS National Research Program WRP No. 20420;Anonymous,1976
2. Reproduction and growth in beef heifers;Bellows;A.I. Dig.,1968
3. Nutrition and reproductive processes in beef cattle;Dunn,1980
4. Reproductive performance and growth of shorthorn purebred and crossbred cows;Fahmy;Anim. Prod.,1971
5. Epidemiology and control of gastrointestinal nematodes of cattle in Virginia;Hansen,1985