APA (7th ed.) Citation

Schulzinger, R. D. (1990). American diplomacy in the twentieth century (2. ed.). Oxford Univ. Pr.

Chicago Style (17th ed.) Citation

Schulzinger, Robert D. American Diplomacy in the Twentieth Century. 2. ed. New York u.a: Oxford Univ. Pr, 1990.

MLA (9th ed.) Citation

Schulzinger, Robert D. American Diplomacy in the Twentieth Century. 2. ed. Oxford Univ. Pr, 1990.