1. Barth, R., Ash, J., & Hacking, S. (1986). Identifying, screening and engaging high-risk clients in private non-profit child abuse prevention programs. Child Abuse & Neglect, 10, 99–106.
2. Belsky, J., & Rovine, M. (1990). Patterns of marital change across the transition to parenthood. Journal of Marriage and the Family, 52, 5–19.
3. Bronfenbrenner, U. (1979). The ecology of human development: Experiments by nature and design. Cambridge: Harvard University Press.
4. Bureau of the Census. (1999). USA counties 1998 on CD-ROM (machine-readable data files) prepared by the Bureau of the Census. Washington: The Bureau (Producer and distributor).
http://govinfo.library.orst.edu/stateis.html
. Accessed 1 May 2001.
5. Clark, J., & Winje, C. (1998). Participant engagement and retention in health related programs: Literature review. Unpublished manuscript, National Committee to Prevent Child Abuse, Chicago, IL.