World Health Organization. (1990). Facts about WHO. World Health Organization.
Citazione stile Chigago Style (17a edizione)World Health Organization. Facts About WHO. Switzerland: World Health Organization, 1990.
Citatione MLA (9a ed.)World Health Organization. Facts About WHO. World Health Organization, 1990.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.