“Comparative Study of Dexmedetomidine and Fentanyl as an Adjuvant to Epidural Bupivacaine for Post-operative Pain Relief in Hepato-biliary Pancreatic Surgery”, Anwer Khan Mod Med Coll J, vol. 10, no. 2, pp. 143–149, Nov. 2019, doi: 10.3329/akmmcj.v10i2.44127.