Study of effect of fentanyl and tramadol added to low dose bupivacaine in subarachnoid block for caesarean section – a comparative study. Journal of the Bangladesh Society of Anaesthesiologists, [S. l.], v. 25, n. 2, p. 41–47, 2014. DOI: 10.3329/jbsa.v25i2.60983. Disponível em: https://banglajol.info/index.php/JBSA/article/view/60983. Acesso em: 29 jun. 2026.