1. Abramson, Y., Seligman, M. E. P., & Teasdale, J. D. (1978). Learned helplessness in humans: Critique and reformulation.Journal of Abnormal Psychology, 87 49?74.
2. American Psychiatric Association. (1980).Diagnostic and statistical manual of mental disorders (3rd ed.). Washington, DC: Author.
3. American Psychiatric Association. (1987).Diagnostic and statistical manual of mental disorders ? revised (3rd ed.). Washington, DC: Author.
4. Amsel, R., & Fichten, C. S. (1990). Ratio versus frequency scores: Focus of attention and the balance between positive and negative thoughts.Cognitive Therapy and Research, 14 257?277.
5. Barlow, D. H. (1987). The classification of anxiety disorders. In G. R. Tischler (Ed.),Diagnosis and classification in psychiatry: A critical appraisal of DSM-III. Cambridge, England: Cambridge University Press.