Gupta, A., Tiwari, T., Kapoor, R., Malik, A., Abbas, H. and Singh, P.R. 2018. Comparative study of ropivacaine with ropivacaine-fentanyl and ropivacaine-fentanyl- magnesium sulfate in epidural anesthesia for lower limb surgeries. International Surgery Journal. 5, 4 (Mar. 2018), 1300–1305. DOI:https://doi.org/10.18203/2349-2902.isj20181010.