American Journal of Obstetrics and Gynecology
American Journal of Obstetrics and Gynecology > 1998 > 178 > 3 > 484-490
American Journal of Obstetrics and Gynecology > 1998 > 179 > 3 > 788-793
American Journal of Obstetrics and Gynecology > 1998 > 179 > 4 > 974-977