TY  - RPRT
TI  - Measuring contraceptive effectiveness: a conceptual framework.
AU  - J B Stanford
PY  - 1997
DO  - 10.1016/s0029-7844(97)84261-5
UR  - https://pubmed.ncbi.nlm.nih.gov/8990461/
ID  - 8990461
ER  -