- Air pilots.2
- Fitzmaurice, James C., 1898-1965.2
- Köhl, Hermann, 1888-1938.2
- Aeronautics.1
- Hünefeld, E. G. (Ehrenfried Günther), Freiherr von, 1892-1929.1
- Hünefeld, E. G. (Ehrenfried Günther), Freiherr von, 1892-1929.1
- Kellogg, Frank B. (Frank Billings), 1856-1937.1
- Speeches, addresses, etc., English.1