DR ALOK PRATAP SINGH, “A COMPARATIVE STUDY OF INTRATHECAL BUPIVACAINE WITH BUPIVACAINETRAMADOL AND BUPIVACAINE-FENTANYL FOR POST-OPERATIVE PAIN RELIEF IN LOWER ABDOMINAL AND LOWER LIMB SURGERIES”, ijpbs, vol. 6, no. 4, pp. 752–758, Dec. 2015.