Al Maruf, Abdullah, Iqbal Hosain Chowdhury, Kazi Ashkar Lateef, Manzoorul Haq Laskar, and Md Mustafa Kamal. “Epidural Administration of Ketamine or Fentanyl With Bupivacaine for Postoperative Analgesia – A Comparative Study”. Journal of the Bangladesh Society of Anaesthesiologists 22, no. 1 (February 26, 2014): 21–25. Accessed January 30, 2023. https://banglajol.info/index.php/JBSA/article/view/18097.