Penson, MRCP, MD, R. T., Joel, PhD, S. P., Gloyne, BSc, A., Clark, BSc, S. and Slevin, FRCP, MD, M. L. (2005) “Morphine analgesia in cancer pain: Role of the glucuronides”, Journal of Opioid Management, 1(2), pp. 83–90. doi: 10.5055/jom.2005.0021.