Demography, 5(2), 931-940
The recent advent of national family planning programs and the expansion of local programs have created an acute need for accurate statistical evaluation of contraceptive methods. Effectiveness in terms of pregnancy rates and continuation or discontinuation of use of the contraceptive method or methods under study have emerged as the major criteria in such evaluations.
Tietze, C., & Lewit, S. (1968). Statistical evaluation of contraceptive methods: use-effectiveness and extended use-effectiveness. *Demography*, *5*(2), 931-940. https://doi.org/10.2307/2060282
Tietze C, Lewit S. Statistical evaluation of contraceptive methods: use-effectiveness and extended use-effectiveness. Demography. 1968;5(2):931-940. doi:10.2307/2060282
Tietze, C., and S. Lewit. "Statistical evaluation of contraceptive methods: use-effectiveness and extended use-effectiveness." *Demography*, vol. 5, no. 2, 1968, pp. 931-940.