1. Pain and some factors that modify it;Beecher;Anesthesiology,1951
2. Pain mechanisms;Melzack;Science,1965
3. Operant conditioning in the treatment of chronic pain;Fordyce;Arch Phys Med Rehabil,1973
4. a list with definitions and notes on usage. Recommended by the IASP Subcommittee on Taxonomy;Pain;Pain,1979
5. Pain and behavioral medicine;Turk,1983