1. Mathews T, Curtin M, MacDorman M: Infant Mortality Statistics from the 1998 Period Linked Birth/Infant Death Data Set. U.S. Department of Health and Human Services, CDC, NCHS. National Vital Statistics Reports. 2000, 48 (12): 1-9.
2. U.S. Department of Health and Human Services.: Healthy People 2000: National Health Promotion and Disease Prevention Objectives. Washington, D.C., HHS, Public Health Service. 1991
3. U.S. Department of Health and Human Services.: Tracking Healthy People 2010. Washington, D.C., HHS, Public Health Service. 2000
4. D.C. Department of Health.: State Center for Health Statistics. Washington, D.C. 1997
5. American College of Obstetricians and Gynocologists: Standards for Obstetric-Gynecologic Services. Chicago, Ill, American College of Obstetricians and Gynecologists. 1994