1. HaubC. and KentM. (1988).World Population Data Sheet, Population Reference Bureau, Washington
2. HatcherR.A., KowalD., GuestP. et al. (1989).Contraceptive Technology: International Edition. Printed Matter Inc., Atlanta, p. 21
3. Gallen, M.E., Lisken, L. and Kak, N. (1987). Men-new focus in family planning.Pop. Rep. Series J.,33
4. TrussellJ. and KostK. (1987). Contraceptive failure in the United States: a critical review of the literature.Stud. Fam. Plann.,18 (5), 237–283
5. FreeM.J. and AlexanderN.J. (1976). Male contraception without a prescription: a reevaluation of the condom and coitus interruptus.Public Health Rep.,91, 437–445