APA (7th ed.) Citation

O'Neill, E. G. (1956). Long day's journey into night. Yale University Press.

Chicago Style (17th ed.) Citation

O'Neill, Eugene Gladstone. Long Day's Journey into Night. New Haven: Yale University Press, 1956.

MLA (9th ed.) Citation

O'Neill, Eugene Gladstone. Long Day's Journey into Night. Yale University Press, 1956.