World Health Organization. (1994). Contraceptive method mix: Guidelines for policy and service delivery. World Health Organization.
Citazione stile Chigago Style (17a edizione)World Health Organization. Contraceptive Method Mix: Guidelines for Policy and Service Delivery. Geneva: World Health Organization, 1994.
Citatione MLA (9a ed.)World Health Organization. Contraceptive Method Mix: Guidelines for Policy and Service Delivery. World Health Organization, 1994.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.