Keshava Murthy MR, and Vikas KN. “A Comparative Study of Cardiovascular Response and Analgesic Effects of Bupivacaine and Butorphanol”. Academia Anesthesiologica International 4, no. 2 (December 31, 2019): 312-316. Accessed April 19, 2024. http://aijournals.com/index.php/aan/article/view/1238.