1. Baker, S. A., Thalberg, S. P., and Morrison, D. M. (1988). Parents' behavioral norms as predictors of adolescent sexual activity and contraceptive use. Adolescence, 23: 265-282.
2. Bearman, P. S., Jones, J., and Udry, J. R. (1998). The National Longitudinal Study of Adolescent Health: Research Design. Retrieved January 15, 1999, from http:/www.cpc.unc.edu/projects/addhealth/design.html
3. Billy, J. O., and Moore, D. E. (1992). A Multilevel Analysis of Marital and Nonmarital Fertility in the U.S. Soc. Forces, 70: 977-1011.
4. Billy, J. O., Wenzlow, A. T., and Grady, W. R. (1998). The National Longitudinal Study of Adolescent Health: Part 1, Codebooks for the Waves I and II Contextual Database. Retrieved September 20, 1999, http://www.cpc.unc.edu/projects/addhealth/codebk1.html
5. Bingham, C. R., Miller, B. C., and Adams, G. R. (1990). Correlates of age at first sexual intercourse in a national sample of young women. J. Adolesc. Res. 5: 18-33.