R. Ahmed, M. S. A. Shaheen, P. K. Sarker, S. P. Roy, and M. N. A. Alam, “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.