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”. Academia Anesthesiologica International, Vol. 4, no. 2, Oct. 2019, pp. 164-9, doi:10.21276/aan.2019.4.2.37.