1. The Anxiety States;Portnoy,1959
2. Diagnostic and Statistical Manual of Mental Disorders, Second Edition, American Psychiatric Association, Washington, D.C., 1968, p. 39.
3. Noyes’ Modern Clinical Psychiatry;Kolb,1968
4. Anxiety Reaction;Lief,1967
5. Neurocirculatory Asthenia (Anxiety Neurosis, effort syndrome, neurasthenia);Wheeler;JAMA,1950