APA (7th ed.) Citation

Kaler, J. B., & Aller, L. H. (1974). The expansion and possible structure of the planetary nebula NGC 2440. University of California.

Chicago Style (17th ed.) Citation

Kaler, James B., and Lawrence Hugh Aller. The Expansion and Possible Structure of the Planetary Nebula NGC 2440. Los Angeles: University of California, 1974.

MLA (9th ed.) Citation

Kaler, James B., and Lawrence Hugh Aller. The Expansion and Possible Structure of the Planetary Nebula NGC 2440. University of California, 1974.