APA (7th ed.) Citation

Schulzinger, R. D. (1990). American diplomacy in the twentieth century (Second edition.). Oxford University Press.

Chicago Style (17th ed.) Citation

Schulzinger, Robert D. American Diplomacy in the Twentieth Century. Second edition. New York: Oxford University Press, 1990.

MLA (9th ed.) Citation

Schulzinger, Robert D. American Diplomacy in the Twentieth Century. Second edition. Oxford University Press, 1990.