Saxena, D., Sanwatsarkar, S., Dixit, A. and Arya, B. 2017. Comparative study of duration of analgesia with epidural bupivacaine and bupivacaine with tramadol in lower limb surgeries. International Journal of Research in Medical Sciences. 5, 5 (Apr. 2017), 2003–2010. DOI:https://doi.org/10.18203/2320-6012.ijrms20171833.