CHAUDHARI, V. L.; THAKARE, A. B.; ZANWAR, Y. N. Epidural Butorphanol : Comparison of two different doses in Lower abdominal surgery. International Journal of Health and Clinical Research, [S. l.], v. 3, n. 10, p. 182–186, 2020. Disponível em: https://ijhcr.com/index.php/ijhcr/article/view/337. Acesso em: 4 mar. 2026.