Jacobsen, MS, MPH, R., Sjøgren, MD, DMS, P., Møldrup, PhD, C. and Christrup, PhD, L. (2007) “Physician-related barriers to cancer pain management with opioid analgesics: A systematic review”, Journal of Opioid Management, 3(4), pp. 207–214. doi: 10.5055/jom.2007.0006.