APA (7th ed.) Citation

Littmann, M., & Yeomans, D. K. (1985). Comet Halley: Once in a lifetime. American Chemical Society.

Chicago Style (17th ed.) Citation

Littmann, Mark, and Donald K. Yeomans. Comet Halley: Once in a Lifetime. Washington, D.C: American Chemical Society, 1985.

MLA (9th ed.) Citation

Littmann, Mark, and Donald K. Yeomans. Comet Halley: Once in a Lifetime. American Chemical Society, 1985.