Authors: SIMPSON JL GRAY RH PEREZ A MENA P BARBATO M CASTILLA EE KAMBIC RT PARDO F TAGLIABUE G STEPHENSON WS BITTO A LI C JENNINGS VH SPIELER JM QUEENAN JT

Citation: Jl. Simpson et al., PREGNANCY OUTCOME IN NATURAL FAMILY-PLANNING USERS - COHORT AND CASE-CONTROL STUDIES EVALUATING SAFETY, Advances in contraception, 13(2-3), 1997, pp. 201-214