Gazi, M. B., R. K. Sakata, and A. M. Issy. “Intra-Articular Morphine Versus Bupivacaine for Knee Motion Among Patients With Osteoarthritis: Randomized Double-Blind Clinical Trial”. São Paulo Medical Journal, vol. 126, no. 6, Nov. 2008, pp. 309-13, https://periodicosapm.emnuvens.com.br/spmj/article/view/2031.