American Aircraft of World War II: Provides reference information on US aircraft used or designed during World War II. Includes photos and links

Pan American Heritage Web Site: Site of the Pan Am Historical Foundation. Provides a comprehensive airline history, lists of the clippers, image library, and former employee resources, as well as foundation newsletter and related links

The Aerodrome: Comprehensive WWI aviation site featuring aces, aircraft they piloted, relevant books, and reference resources. Interactive features include a forum and guestbook