DTIC ADA280302: Aerodynamic Characteristics of Airfoils. Volume 4. (1927)
Defense Technical Information Center · leaf 22
Drag Coefficient (Absolute).
DTIC Archive · National aeronautics and space administration washington dc · *aerodynamic characteristics · Structural properties · Aerodynamic drag · Wings · Airfoils
Internet Archive · Public domain (published before 1931). Free to use for anything.