APA (7th ed.) Citation

Langley, S. P., Langley, S. P., & Manly, C. M. (1911). Langley memoir on mechanical flight. Smithsonian Inst.

Chicago Style (17th ed.) Citation

Langley, Samuel P., Samuel P. Langley, and Charles M. Manly. Langley Memoir on Mechanical Flight. Washington: Smithsonian Inst, 1911.

MLA (9th ed.) Citation

Langley, Samuel P., et al. Langley Memoir on Mechanical Flight. Smithsonian Inst, 1911.