(2024). Postage stamp prices: United States, United Nations, Canada & provinces : Confederate States, U.S. possessions, U.S. trust territories, and comprehensive U.S. stamp identifier (2025 edition, 90th edition.). H.E. Harris & Co./Whitman Publishing.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Postage Stamp Prices: United States, United Nations, Canada & Provinces : Confederate States, U.S. Possessions, U.S. Trust Territories, and Comprehensive U.S. Stamp Identifier. 2025 edition, 90th edition. Florence, AL: H.E. Harris & Co./Whitman Publishing, 2024.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Postage Stamp Prices: United States, United Nations, Canada & Provinces : Confederate States, U.S. Possessions, U.S. Trust Territories, and Comprehensive U.S. Stamp Identifier. 2025 edition, 90th edition. H.E. Harris & Co./Whitman Publishing, 2024.