Bywaters, Barbara L., "Marriage, Madness, and Murder in Sophie Treadwell's Machinal," in Modern American Drama: The Female Canon, edited by June Schlueter, Associated University Presses, 1990, pp. 97—110.

Dickey, Jerry, "The 'Real Lives' of Sophie Treadwell: Expressionism and the Feminist Aesthetic in Machinal and For Saxophone," in Speaking the Other Self: American Women Writers, edited by Jeanne Campbell Reesman, University of Georgia Press, 1997, pp. 176—84.

Tancheva, Kornelia, "Sophie Treadwell's Play Machinal: Strategies of Reception and Interpretation," in Experimenters, Rebels, and Disparate Voices: The Theatre of the 1920s Celebrates American Diversity, edited by Arthur Gewirtz and James J. Kolb, Praeger, 2003.

Treadwell, Sophie, Machinal, Nick Hern Books, 1993.