APA (7th ed.) Citation

Costain, T. B. (1949). The conquerors. Doubleday.

Chicago Style (17th ed.) Citation

Costain, Thomas Bertram. The Conquerors. Garden City, N.Y: Doubleday, 1949.

MLA (9th ed.) Citation

Costain, Thomas Bertram. The Conquerors. Doubleday, 1949.