Cita APA (7th ed.)
United States Postal Service & United States Postal Service. International Postal Rates and Fees.
Cita Chicago (17th ed.)
United States Postal Service i United States Postal Service. International Postal Rates and Fees.
Cita MLA (9th ed.)
United States Postal Service i United States Postal Service. International Postal Rates and Fees.
Atenció: Aquestes cites poden no estar 100% correctes.