1. Abramson, L. Y., Seligman, M. E. P., & Teasdale, J. D. (1978). Learned helplessness in humans: Critique and reformulation. Journal of Abnormal Psychology, 87, 49–74.
2. Achor, R. W. P., Hanson, N. O., & Gifford, R. W., Jr. (1955). Hypertension treated with Rauwolfia serpentina(whole root) and with reserpine: Controlled study disclosing occasional severe depression, Journal of the American Medical Association, 159, 841–845.
3. Adler, G., & Buie, D. H., Jr. (1979). Aloneness and borderline psychopathology: The possible relevance of child development issues. International Journal of Psycho-Analysis, 60, 83–96.
4. Agren, J., & Terenius, L. (1983). Depression and CSF endorphin fraction I: Seasonal variation and higher levels of unipolar than bipolar patients. Psychiatry Research, 10, 303–311.
5. American Psychiatric Association (1980). Diagnostic and statistical manual of mental disorders, 3rd ed. Washington, DC: Author.