1. Tests of Pressurized Cabin Structures, by W. L. Howland and C. F . Beed; Journal of theAeronautical Sciences, November 1940, pages17-23.
2. Engineering for the Higher Altitudes, by Wellwood E. Beall; Aero Digest, October 1940, pages52-56.
3. High Pressure Flying, by Ross L. Cunningham; Flying and Popular Aviation, September 1940, pages12-14.
4. Why Fly High, by Brian Worley; Aeronautics, August 1940, pages58-61.