APA (7th ed.) Citation

Abell, G. O. (1969). Exploration of the universe / by G. Abell (2nd ed.). Holt, Rinehart and Winston.

Chicago Style (17th ed.) Citation

Abell, George O. Exploration of the Universe / by G. Abell. 2nd ed. Holt, Rinehart and Winston, 1969.

MLA (9th ed.) Citation

Abell, George O. Exploration of the Universe / by G. Abell. 2nd ed. Holt, Rinehart and Winston, 1969.

Warning: These citations may not always be 100% accurate.