@inbook{6092707,
author={Peter C. Panus and Erin E. Jobst and Susan B. Masters and Bertram Katzung and Suzanne L. Tinsley and Anthony J. Trevor},
title={Chapter 20. Opioid Analgesics and Antagonists},
booktitle={Pharmacology for the Physical Therapist},
publisher={The McGraw-Hill Companies},
address={New York, NY},
year={2009},
url={accessphysiotherapy.mhmedical.com/content.aspx?aid=6092707}
}