American Journal of Obstetrics and Gynecology
American Journal of Obstetrics and Gynecology > 2006 > 194 > 1 > 268-273
American Journal of Obstetrics and Gynecology > 2006 > 195 > 4 > 1053-1057
American Journal of Obstetrics and Gynecology > 2009 > 200 > 6 > 665.e1-665.e5
American Journal of Obstetrics and Gynecology > 2011 > 204 > 5 > 450.e15-450.e20