Epidural administration of ketamine or fentanyl with bupivacaine for postoperative analgesia – A comparative study. j Bangladesh Soc Anaesthesiologists [Internet]. 2014 Feb. 26 [cited 2026 Jul. 21];22(1):21-5. Available from: https://www.banglajol.info/index.php/JBSA/article/view/18097