APA (7th ed.) Citation

Abell, G. O., Morrison, D., & Wolff, S. C. (1991). Exploration of the universe (6th Edition, 1993 Version.). Saunders College Publishing.

Chicago Style (17th ed.) Citation

Abell, George O., David Morrison, and Sidney C. Wolff. Exploration of the Universe. 6th Edition, 1993 Version. Philadelphia: Saunders College Publishing, 1991.

MLA (8th ed.) Citation

Abell, George O., et al. Exploration of the Universe. 6th Edition, 1993 Version. Saunders College Publishing, 1991.