1. United States Department of Agriculture, National Agriculture Statistics Service. 1997 census of agriculture. Available at: http://www.nass.usda.gov/census/census97/volume1/us-51/us1_02.pdf. Accessed February 2003.
2. Characteristics and production costs of US cow-calf operations;Short,2001
3. Livestock Marketing Information Center, 2002. Annual January 1 cattle investor by state. Available at: http://www.lmic.info/tac/spreadsheets/spreadsheets.html. Accessed February 2003.
4. Biological types of cattle;Cundiff,1999
5. The national beef quality audit. Colorado State University, Texas A&M, College Station, and Oklahoma State University, for the National Cattlemen's Beef Association;Smith,1995