2Franca F,Johannes B. Review of clinical experience with estradiol in combinedoral contraceptives [ J ]. Contraception, 2010,81 ( 1 ) : 8 - 15.
3Oppegaard KS, Lieng M. A combination of misoprostol and estradiol for preoperative cervical ripening in postmenopausal women: a randomised controlled trial[ J]. BJOG,2010,117( 1 ) :53 -61.
