Kumkum Gupta, Pavitra Kalra, Prashant K Gupta, Salony Agarwal, Abhishake Kumar, and Iqraa Khanum, “Clonidine versus Tramadol as Adjuvant to Epidural Anaesthesia With 0.5% Bupivacaine for Lower Limb Orthopaedic Procedures”, AAN, vol. 4, no. 2, pp. 164-169, Oct. 2019.