1[2]Nygaard I,Bradley C,Brandt D,et al.Pelvic prolapse in older women:prevalence and risk factors.Obstet Gynecol,2004,104:489.
2[3]Swift S,Woodman P,O'Boyle A,et al.Pelvic organ support study:the distribution,clinical definition,and epidemiologic condition of pelvic organ support defects.Am J Obstet Gynecol,2005,192:795.