APA (7th ed.) Citation

ABELL, G. O. (1980). Realm of the universe.-- Ed.2. Saunders College.

Chicago Style (17th ed.) Citation

ABELL, George O. Realm of the Universe.-- Ed.2. Philadelphia: Saunders College, 1980.

MLA (9th ed.) Citation

ABELL, George O. Realm of the Universe.-- Ed.2. Saunders College, 1980.