1. Agricultural Research Service 1961 A leader's guide to agriculture's defense against biological warfare and other outbreaks. ARS Special Report ARS 22-75 U.S. Department of Agriculture Washington, D.C
2. Biosecurity consideration for pork production units;Amass;Swine Health Prod,1999
3. Animal and Plant Health Inspection Service 1999 Regional Emergency Animal Disease Eradication Organization (READEO) Manual Emergency Program. APHIS U.S. Department of Agriculture Washington, D.C
4. Animal and Plant Health Inspection Service 1999 National Animal Health Monitoring System (NAHMS) Part III. The U.S. Pork Industry 1990-1995 U.S. Department of Agriculture Washington, D.C