KUMARI, K.; SWAROOP, N.; SHARMA, P.; SETH, S.; KANTI, V.; KUMAR, D. Intravenous infusion of tramadol - a safe labour analgesia. International Journal of Reproduction, Contraception, Obstetrics and Gynecology, [S. l.], v. 4, n. 4, p. 1044–1047, 2017. DOI: 10.18203/2320-1770.ijrcog20150423. Disponível em: https://www.ijrcog.org/index.php/ijrcog/article/view/2055. Acesso em: 26 oct. 2025.