1. Aschelmann, S. R., & Williams, M. L. (1989). A test of the response deprivation hypothesis in a multiple-response context. American Journal on Mental Retardation, 93, 345–353.
2. Barnes-Holmes, D., Barnes-Holmes, Y., & Cullinan, V. (2001). Relational frame theory and Skinner’s Verbal Behavior. The Behavior Analyst, 23, 69–84.
3. Berkson, G., & Mason, W. A. (1964). Stereotyped movement of mental defectives, IV. The effects of toys and characteristic acts. American Journal of Mental Deficiency, 68, 588–524.
4. Bijou, S. W. (1996). Reflections on some early events related to behavior analysis of child development. The Behavior Analyst, 19, 49–60.
5. Boch, S., & Fuqua, R. W. (2001). Behavioral cusp: A model for selecting target behaviors. Journal of Applied Behavior Analysis, 34, 123–125.