1. AGRAS, W. S., KAZDIN, A. E., & WILSON, G. T. (1979). Behavior therapy. San Francisco: W. H. Freeman.
2. BANDURA, A. (1982). Self-efficacy mechanism in human agency. American Psychologist, 37, 122–147.
3. Behavior Research and Therapy. (1987). 25(3), (inside back cover).
4. EPSTEIN, L. H., & WING, R. R. (1984). Behavioral contracting: Health behaviors. In C. M. Franks (Ed.), New developments in behavior therapy: From research to clinical application (pp. 409–449). New York: Haworth Press.
5. ERICKSON, R. C. (1973). “Free will” and clinical research. Psychotherapy: Theory Research, and Practice, 10, 10–13.