References
- Krupp NE: Psychiatric complications of chronic and crippling illness. Psychosomatics 9: 109–113, 1968
- Rusk HA: Rehabilitation Medicine: A Textbook on Physical Medicine and Rehabilitation. Ed 2. St. Louis, The CV Mosby Co, 1964
- Seneca LA, cited by Evans B: Dictionary of Quotations. New York, Delacorte Press, 1968