7Wiebe E, Dunn S, Guilbert E, et al. Comparison of abortions induced by methotrexate or mifepristone followed by misoprostol [J]. Obstet Gynecol, 2002,99(5) :813-819.
8Jain JK, Dutton C, Harwood B, et al. A prospective randomized, double-blinded, placebo-controlled trial comparing mifepristone and vaginal misoprostol to vaginal misoprostol alone for elective termination of early pregnancy[J]. Hum Reprod, 2002, 17 (6) : 1477-1482.