1. U.S. Public Health Service.Healthy People 2000: National Health Promotion and Disease Prevention Objectives.Washington, DC: U.S. Dept, of Health and Human Services, U.S. Public Health Service; 1990. U.S. Dept, of Health and Human Services publication PHS 91-50212.
2. Low vaccination levels of U.S. preschool and school-age children: retrospective assessments of vaccination coverage, 1991-1992;Zell;JAMA.,1994
3. Standards for Pediatric Immunization Practices;JAMA,1993
4. The State of America's Children,1992
5. U.S. General Accounting Office. Vaccines for Children: Critical Issues in Design and Implementation. Washington, DC: U.S. General Accounting Office; 1994.