APA (7th ed.) Citation

Carr, E. H. (1940). The twenty years' crisis 1919 - 1939: An introduction to the study of international relations. Macmillan.

Chicago Style (17th ed.) Citation

Carr, Edward Hallett. The Twenty Years' Crisis 1919 - 1939: An Introduction to the Study of International Relations. London: Macmillan, 1940.

MLA (8th ed.) Citation

Carr, Edward Hallett. The Twenty Years' Crisis 1919 - 1939: An Introduction to the Study of International Relations. Macmillan, 1940.