Brustein, Robert. "Eugene O'Neill," in The Theatre of Revolt: An Approach to the Modern Drama, Little, Brown, & Co. 1964, pp. 329-59.

Carpenter, Frederic I. Eugene O'Neill, Twayne Publishers, 1979.

Clark, Barrett H. Eugene O'Neill: The Man and His Plays, Dover, 1947.

De Voto, Bernard. "Minority Report," in Playwright's Progress: O'Neill and the Critics, edited by Jordan Miller, Scott, Foresman, & Co., 1965, pp. 108-12.

Jensen, George H. "Eugene O'Neill," in Dictionary of Literary Biography, Volume 7, edited by John MacNicholas, Gale Research, 1981, pp. 141-63.

Black, Stephen A. Eugene O'Neill: Beyond Mourning and Tragedy, Yale University Press, 1999, 480 p.

A comprehensive, well-documented biography of O'Neill.

Bloom, Harold, ed. Eugene O'Neill Chelsea House, 1988, 183 p.

Collection of critical essays on O'Neill's work.

Bogart, Travis, ed. Selected Letters of Eugene O'Neill, Yale University Press, 1988, 602 p.

O'Neill's collected letters provide insight into his life and work.

Stroupe, John H., ed. Critical Approaches to O'Neill, AMS Press, 1988.

Comprised of critical essays...