1. Bakker K. (1997). Instrumentation for the assessment and treatment of stuttering. In R. F. Curlee & G. M. Siegel (Eds.) Nature and treatment of stuttering: New directions (2nd ed. pp. 377-397). Boston: Allyn and Bacon.
2. Barlow D. H. & Hersen M. (1984). Single case experimental designs: Strategies for studying behavior change (2nd ed.). New York: Pergamon.
3. An exploratory attempt to isolate types of stuttering [abstract];Berlin A. J.;Speech Monographs,1955
4. Conditions under which Stuttering is Reduced or Absent: A Review of Literature
5. Bloodstein O. (1995). A handbook on stuttering (5th ed.). San Diego CA: Singular.