4Ashok PW,Templeton A,Wagaarach chi PT,Flett GM.Midtrimester medical termination of pregnancy:a review of 1002 consecutive cases.Contraception,2004,69(1):51～58.
5Ngai SW,Tang OS,Ho PC.Randomized comparison of vaginal (200 microg every 3 h) and oral (400 microg every 3 h) misoprostol when combined with mifepristone in termination of second trimester pregnancy.Hum Reprod,2000,15(10):2205～2208.
6Tang OS,C h an CC,Kan AS,Ho PC.A prospective randomized comparison of sublingual and oral misoprostol w h en combined with mifepristone for medical abortion at 12-20 weeks gestation.Hum Reprod,2005,20(11):3062～3066.
