Annual report - National Advisory Committee for Aeronautics (1915)
United States. National Advisory Committee for Aeronautics · Washington, U.S. Govt. Print. Off · leaf 328
Aerodynamic characteristics of aerofoils. 283 Center of Pressure In Percent of Chord from Leading Edge Center of Pressure in Percent of Chord from Leading Edge
Aeronautics · Aeronautics, Military · United States. National Advisory Committee for Aeronautics · Aeronautics -- United States -- Periodicals · Aeronautics, Military -- United States -- Periodicals
Internet Archive · Smithsonian Libraries · Public domain (published before 1931). Free to use for anything.