Cita APA (7a ed.)
United Nations Postal Administration. Postal Issues of the United Nations 1951-1986.
Cita Chicago Style (17a ed.)
United Nations Postal Administration. Postal Issues of the United Nations 1951-1986.
Cita MLA (9a ed.)
United Nations Postal Administration. Postal Issues of the United Nations 1951-1986.
Precaución: Estas citas no son 100% exactas.