APA (7th ed.) Citation

Collis, J. S. (1976). Christopher Columbus. Sphere Books.

Chicago Style (17th ed.) Citation

Collis, John Stewart. Christopher Columbus. Cardinal: Sphere Books, 1976.

MLA (9th ed.) Citation

Collis, John Stewart. Christopher Columbus. Sphere Books, 1976.

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