Kapse, Upendrakumar S., and Pradnya M. Bhalerao. “Comparison of Bupivacaine With Fentanyl and Bupivacaine With Butorphanol for Brachial Plexus Block by Axillary Approach- a Prospective, Double Blind, Randomized Study”. International Journal of Research in Medical Sciences 5, no. 4 (March 28, 2017): 1415–1418. Accessed December 2, 2023. https://www.msjonline.org/index.php/ijrms/article/view/2128.