APA (7th ed.) Citation

Helms, J. L., & Poritzky, S. B. (1982). National airspace system plan. Astronautics & Aeronautics, 20, 50.

Chicago Style (17th ed.) Citation

Helms, J. L., and S. B. Poritzky. "National Airspace System Plan." Astronautics & Aeronautics 20 (1982): 50.

MLA (9th ed.) Citation

Helms, J. L., and S. B. Poritzky. "National Airspace System Plan." Astronautics & Aeronautics, vol. 20, 1982, p. 50.