“Randomized Controlled Study F Entanyl Vs Buprenorphine As Adjuvants in Subarachnoid Block With 2-Chloroprocaine in Anorectal Surgery ”. Asian Journal of Pharmaceutical and Health Sciences 10, no. 3 (September 30, 2020): 2348–2354. Accessed February 27, 2026. https://www.ajphs.com/index.php/ajphs/article/view/605.