1. The epidemiology of cancer pain;Goudas;Cancer Invest,2005
2. Cancer pain relief,1996
3. NCCN practice guidelines for cancer pain;Benedetti;Oncology,2000
4. Summary version of the standards, options and recommendations for the use of analgesia for the treatment of nociceptive pain in adults with cancer (update 2002);Krakowski;Br J Cancer,2003
5. Principles of analgesic use in the treatment of acute pain and cancer pain,2008