1. Teenagers in the united states: Sexual activity, contraceptive use, and childbearing, 2002. National Center for Health Statistics;Abma;Vital Health Statistics,2004
2. Preconceptional Care: ACOG technical bulletin No. 205—May 1995;International Journal of Gynecology and Obstetrics,2005
3. Folic acid for the prevention of neural tube defects;Pediatrics,1999
4. Preventive care in the emergency department: diagnosis and management of smoking and smoking-related illness in the emergency department: a systematic review;Bernstein;Academic Emergency Medicine,2002
5. Centers for Disease Control and Prevention (CDC). (1999). The national plan to eliminate syphilis from the United States. Available: http://www.cdc.gov/StopSyphilis/SEEPlan2006.pdf.