World Health Organization. (1999). Sexually transmitted infections prevalence study methodology. World Health Organization.
Citazione stile Chigago Style (17a edizione)World Health Organization. Sexually Transmitted Infections Prevalence Study Methodology. Geneva,Switzerland: World Health Organization, 1999.
Citatione MLA (8a ed.)World Health Organization. Sexually Transmitted Infections Prevalence Study Methodology. World Health Organization, 1999.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.