5Zalel Y, Shulman A, Lidor A, et al. The local progestational efffect of the levonorgestrel-releasing intrauterine system: a sonographic and Doppler flow study. Hum Reprod, 2002, 17(11):2878-2880.
6Guillebaud .I. The levnorgestrel intrauterine systemL: a clinical perspective from the UK. Ann N Y Acad Sci, 2003, 997(2): 185-193.
7Backman T, Huhtala S, Luoto R, et al. Advance information improves improves user satisfaction with the levonorgestrel intrauterine system.Obstet Gynecol, 2002, 99(4): 608-613.
8French R, Cowan F, Mansour D, et al. Hormonally impregnated intrauterine systems(IUSs) versus other forms of reversible contraceptives as effective methods of preventing pregnancy. Cochrane Database Syst Rev, 2001,(2):CD001776.
9Backman T, Rauramo I, Huhtala S, et al. Pregancy during the use of levonorgestrel intrauterine system. Am J Obstet Gynecol, 2004, 190(1):50-54.
10Roy SN, Bhattacharya S. Benefits and risks of pharmacological agents used for the treatment of menorrhagia. Drug Saf, 2004, 27(2):75-90.
