APA (7th ed.) Citation

Hartmann, W. K. (1991). Astronomy: The cosmic journey (1991 ed.). Wadsworth.

Chicago Style (17th ed.) Citation

Hartmann, William K. Astronomy: The Cosmic Journey. 1991 ed. Belmont, Calif: Wadsworth, 1991.

MLA (9th ed.) Citation

Hartmann, William K. Astronomy: The Cosmic Journey. 1991 ed. Wadsworth, 1991.