1. Contraception, contraceptive technology, and STDs;Morrison,2008
2. Highly effective contraception and sexually transmitted infections in the Western European context;Morrison,2005
3. Family Planning Worldwide 2008 Data Sheet;Population Reference Bureau,2008
4. World Contraceptive Use, 2003 Chart;United Nations,2003
5. Family Planning Worldwide 2002 Data Sheet;Population Reference Bureau,2002