1. Hahn, Eugene. 1943.Stuttering, Significant Theories and Therapies, 19–26. Standford University Press.
2. Investigations in the Etiology and Nature of Dysphemia and its Symptom, Stuttering
3. 1935. “Sideness as an Etiologic Factor in Stuttering”.Journal of Genetic Psychology, XLVII Sept. Id.