1. Atwater, J. B., & Morris, E. K. (1988). An observational analysis of teachers’ instructions in preschool classrooms. Journal of Applied Behavior Analysis, 21, 157–167.
2. Ayllon, T., & Azrin, N. H. (1968). The token economy. New York: Appleton-Century-Crofts.
3. Baars, B. J. (1986). The cognitive revolution in psychology. New York: Guilford.
4. Branch, M. (1977). On the role of “memory” in the analysis of behavior. Journal of the Experimental Analysis of Behavior, 28, 171–179.
5. Catania, A. C. (1998). Learning ( 4th ed. ). Upper Saddle River, NJ: Prentice-Hall.