1. Pain terms: A current list with definitions and notes on usage;Lindblom;Pain,1979
2. Classification of Chronic Pain: Descriptions of Chronic Pain Syndromes and Definitions of Pain Terms,1994
3. Pain: Psychological and Psychiatric Aspects;Merskey,1967
4. The challenges of pain and suffering;Morris,2003
5. Biological Science: Principles and Patterns of Life;Galbraith,1966