@inbook{3423541, author={Carol A. Warfield and Zahid H. Bajwa}, title={Appendix B: Pain Clinic Records}, booktitle={Principles & Practice of Pain Medicine, 2e}, publisher={The McGraw-Hill Companies}, address={New York, NY}, year={2004}, url={accessanesthesiology.mhmedical.com/content.aspx?aid=3423541} }