1. The Alan Guttmacher Institute (1976). 11 Million Teenagers - What can be Done about the Epidemic of Adolescent Pregnancies in the United States? ( New York: Alan Guttmacher Institute )
2. Population Bulletin;WH Baldwin,1976
3. Fielding, J. E. (1978). Adolescent pregnancy revisited. N. Engl. J. Med., 299, 893
4. National Center for Health Statistics (1977). Teenage Childbearing: United States 1966–75. Monthly Vital Statistics Report: Natality Statistics 26. DHEW publication No. (HRA) 77–1120. ( Washington, DC: US Government Printing Office )
5. The Alan Guttmacher Institute (1981). Teenage Pregnancy: The Problem that hasn’t Gone Away. ( New York: Alan Guttmacher Institute )