Tewari, A. and Singh, A.K. 2020. Comparative evaluation of caudal tramadol and fentanyl when mixed with bupivacaine in paediatric age group. International Journal of Research in Medical Sciences. 8, 4 (Mar. 2020), 1445–1450. DOI:https://doi.org/10.18203/2320-6012.ijrms20201340.