Guttmacher Institute (1992). Choice of Contraceptives. The Medical Letter on Drugs and Therapeutics. 34 (885): 111—114. PMID1448019. Hatcher, RA; Trussel J, Stewart F, et al. (1994). Contraceptive Technology (вид. Sixteenth Revised). New York: Irvington Publishers. ISBN0-8290-3171-5.
Guttmacher Institute (1992). Choice of Contraceptives. The Medical Letter on Drugs and Therapeutics. 34 (885): 111—114. PMID1448019. Hatcher, RA; Trussel J, Stewart F, et al. (1994). Contraceptive Technology (вид. Sixteenth Revised). New York: Irvington Publishers. ISBN0-8290-3171-5.