Theory of literature.

MLA

Wellek, René, and Austin Warren. Theory of Literature. 2nd ed. New York (N.Y.): Harcourt, Brace and World, 1956.

APA

Wellek, R., & Warren, A. (1956). Theory of literature. 2nd ed. New York (N.Y.): Harcourt, Brace and World.

Chicago

Wellek, René., and Austin Warren. Theory of Literature. 2nd ed. New York (N.Y.): Harcourt, Brace and World, 1956.