Falk, D. V. (1958). Eugene O`Neill and the tragic tensión an interprise study of the plays. Rutgers University Press.
Lua i Stíl Chicago (17ú heag.)Falk, Doris V. Eugene O`Neill and the Tragic Tensión an Interprise Study of the Plays. New Yersey: Rutgers University Press, 1958.
Lua MLA (9ú heag.)Falk, Doris V. Eugene O`Neill and the Tragic Tensión an Interprise Study of the Plays. Rutgers University Press, 1958.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.