M. K., Y.; P., S.; D. M., V.; U. K., A. R. A comparative study of epidural tramadol with epidural pentazocine for postoperativeanalgesia in patients undergoing lower abdominal surgeries. International Journal of Basic & Clinical Pharmacology, [S. l.], v. 6, n. 10, p. 2441–2445, 2017. DOI: 10.18203/2319-2003.ijbcp20174373. Disponível em: https://www.ijbcp.com/index.php/ijbcp/article/view/2067. Acesso em: 16 apr. 2026.