Air Mail Stamps: Made to Fly - Philatelic Database

US Stamp Covers Collectors Weekly

Bermuda's Aviation History and pioneers

Egyptian Airmail Stamp Images

US Airmail Stamps - iHobb

Air Mail Stamps: Made to Fly - Philatelic Database

American Air Mail Society – Founded 1923

Scanning the Horizons – American Air Mail Society

Onward Air Transmission - Philatelic Database

Aircraft on Stamps Archives - Philatelic Database

Navigating the Aircraft – American Air Mail Society