1. Worldometer. Current World count..
2. Hurt KJ, Guile MW, Bienstock JL, Fox HE, Wallach EE, Fertility control: contraception, sterilization, and abortion.The Johns Hopkins manual of gynecology and obstetrics.382-95
3. .Medical eligibility criteria for contraceptive use.
4. .Family planning: A global handbook for providers.
5. Langmaid S, Pull out Method (Withdrawal)..