APA (7th ed.) Citation

Smith, R. C., & Smith, R. C. (1993). Vanguard of empire: Ships of exploration in the age of Columbus. Oxford University Press.

Chicago Style (17th ed.) Citation

Smith, Roger C., and Roger Craig Smith. Vanguard of Empire: Ships of Exploration in the Age of Columbus. New York, NY [u.a.]: Oxford University Press, 1993.

MLA (9th ed.) Citation

Smith, Roger C., and Roger Craig Smith. Vanguard of Empire: Ships of Exploration in the Age of Columbus. Oxford University Press, 1993.