Die Luftschiffahrt der Gegenwart

Langley Memoir on Mechanical Flight, Parts I and II Smithsonian Contributions to Knowledge, Volume 27 Number 3, Publication 1948, 1911

Heroic airmen and their exploits

Aeolus; or, the future of the flying machine

The Problem of Manflight

Lecture on Artificial Flight Given by request at the Academy of Natural Sciences

Learning to Fly: A Practical Manual for Beginners

Aircraft

Learning to fly in the U.S. Army

The Aviator and the Weather Bureau

Dirigible Balloons