1. Defining pain terms;de Jong;JAMA,1980
2. Pain terms: list with definitions and notes on usage;IASP;Pain,1979
3. Pain terms: a list with definitions and notes on usage;IASP;Pain,1982
4. Development of a universal language of pain syndromes;Merskey,1983
5. Neurobiology and treatment of pain;Ballas,1994