Haque, M. R. .; Mondal, M. K. .; Roy, B. R. .; Yeasmeen, S. .; Haque, F. .; Islam, N. .; Akhtaruzzaman, A. . Study of Effect of Fentanyl and Tramadol Added to Low Dose Bupivacaine in Subarachnoid Block for Caesarean Section – a Comparative Study. j Bangladesh Soc Anaesthesiologists 2014, 25, 41-47.