1. Income over investment in semen;Everett;J Dairy Sci,1975
2. Genetic change attained and possible;Norman,1992
3. Timeliness and effectiveness of progeny testing through artificial insemination;Norman;J Dairy Sci,2003
4. Bull management practices on California dairies: Implications for education and veterinary services, 2002;Champagne,2002
5. National Animal Health Monitoring System. Reference of dairy health and management in the United States, 2002. http://www.aphis.usda.gov/vs/ceah/ncahs/nahms/dairy/dairy.htm