World Health Organization. (1999). Sexually transmitted infections prevalence study methodology. World Health Organization.
Chicago-Zitierstil (17. Ausg.)World Health Organization. Sexually Transmitted Infections Prevalence Study Methodology. Geneva,Switzerland: World Health Organization, 1999.
MLA-Zitierstil (8. Ausg.)World Health Organization. Sexually Transmitted Infections Prevalence Study Methodology. World Health Organization, 1999.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.