20 cases of fentanyl-associated ataranalgesia. Revista Universidad de Guayaquil, [S. l.], v. 91, n. 3, p. 51–62, 1994. DOI: 10.53591/rug.v91i3.965. Disponível em: https://revistas.ug.edu.ec/index.php/rug/article/view/616. Acesso em: 5 dec. 2025.