TY - JOUR AU - Ebrahim, S H; Gfroerer, J TI - Pregnancy-related substance use in the United States during 1996-1998 JO - Obstet Gynecol IS - 2 VL - 101 PY - 2003 DO - 10.1016/S0029-7844(02)02588-7 SP - 374 EP - 379 ER -