APA (7th ed.) Citation

Bretnor, R. (1980). Orion's sword: War in interstellar and intergalactic space. Ace Books.

Chicago Style (17th ed.) Citation

Bretnor, Reginald. Orion's Sword: War in Interstellar and Intergalactic Space. New York: Ace Books, 1980.

MLA (9th ed.) Citation

Bretnor, Reginald. Orion's Sword: War in Interstellar and Intergalactic Space. Ace Books, 1980.

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