1. Adams, R. D. and Victor, M. (1977).Principles of Neurology, 4th ed. NY: McGraw-Hill, pp. 831–832.
2. Alexander, L., Pigoan M., Myerson A. (1938). Beriberi and Scurvy.Trans. Am. Neurol. Assoc. 64:135.
3. Barclay L., ed. (1993).Clinical Geriatric Neurology. Phil., PA: Lea and Febiger, pp. 45–46.
4. Bleuler, M. (1950).Dementia Praecox or the Group of Schizophrenias. NY: International Universities Press.
5. Cole J. O., Schatzberg A. F. and Frazier S. K. (1976).Depression, Biology, Psychodynamics, and Treatment. NY: Plenum Press, p. 138.