Belmont, L. , & Marolla, F. A. (1973). Birth order, family size and intelligence. Science, 182, 1096-1101.
2.
Bradley, R. W. (1968). Birth order and school related behavior. Psychological Bulletin, 70, 45-51
3.
Erickson, E. H. (1964). Childhood and society (rev. ed.). Toronto: George J. Meleod.
4.
Ezimokhai, M. , Ajabor, L. N., Jackson, M., & Izilien, M. I. (1981). Response of unmarried adolescents to contraceptive advice and service in Nigeria. International Journal of Gynaecology and Obstetrics, 19, 481-485.
5.
Guest, H. H. (1966). Why the schools must teach family life education. Manitoba Teacher, 45 (2),
6.
Hatcher, R. A. , Stewart, G. K., Stewart, F., Guest, F., Shwartz, D. W., & Jones, S. A. (1980). Contraceptive technology. New York: Irvington.
7.
Hawkins, D. F. , & Elder, M. G. (1979). Human fertility control: Theory and practice. London: Butterworth.
8.
Howard, M. (1977). Serving young teens: Problems and possibilities. Paper presented before the APPB/PPFA Meeting, Atlanta, Georgia.
9.
Laycook, S. R. (1967). Family living and sex education: A guide for parents and youth leaders. Toronto: Baxter.
10.
Mecklenburg, F. (1973). Pregnancy: An adolescent crisis. Minnesota Medicine, 56, 101-104.
11.
Omu, A. E. , Oronsaye, A. U., Fall, M. K., & Asuquo, E. E. (1981). Adolescent induced abortion in Berin-City, Nigeria. International Journal of Gynaecology and Obstetrics, 19, 495-499.
12.
Owuamanam, D. O. (1982). Sexual activities of schoolgoing adolescents in Nigeria. Adolescence, 27, 81-87.