The Story of Our Post Office, Marshall Cushing (1893)

Sloane's Column, A great resource for U. S. stamps

U.S. International Postal Rates, 1872-1996, A.S. Wawrukiewicz, essential reference

United States Multiple Advertising and Discount Postal Cards, Bill Falberg,ed.

Sanitary Fairs, A.R. and M.S. Kantor

The Post offices of Massachusetts, Merolla and Crowther

Philately of Switzerland, Richard T. Hall, ed.

Philately of the Third Reich, Postage and Propaganda, Alf Harper

The Shanghai Postal System - Stamps and Postal History, Charles W. Dougan

From Indian Trails to the Birth of a Nation, Spellman Symposium

Cancellations and Killers of the Banknote Era, 1870-94, James M. Cole

United States Supplementary Mail, Leonard Piszkiewicz

American Illustrated Cover Catalog, David D. Phillips auction

Chicago Postal History, Harvey M. Karlen

Post Office Seals of the United States and Possessions, Jim Kotanchik

Tasmania, Stamps and Postal History, Royal Philatelic Society of London

Ma's Illustrated Catalogue of the Stamps of China, rev. 1998 edition - basic reference

American Philatelic Miscellany, Susan McDonald

U.S. Domestic Postal Rates 1872-1999, rev. 2nd ed., Wawrukiewicz-great reference

Presidential Campaign Illustrated Envelopes 1840-1872, James W. Milgram

United States Patriotic Covers of World War II, Lawrence Sherman

History of Letter Communication Between the U.S. and Europe, 2nd ed.Hargest

Identification Guide to U. S. Stamps, 1847-1934, 6th ed., Charles N. Micarelli

British Pictorial Envelopes of the 19th Century, Bodily, Jarvis, and Hahn

The Shanghai Postal System - Stamps and Postal History, Charles W. Dougan