Perea Solano, Darío José, José Ricardo Navarro, Pedro Herrera, Viviana Castillo, Andrea González, Andrés García, and Jaime Galvis. 2012. “Randomized Double-Blind Controlled Clinical Trial for the Evaluation of Post-Partum Analgesia Using Epidural Morphine: Analgesic Effectiveness of Different Dose Regimes Compared With Placebo”. Colombian Journal of Anesthesiology 40 (1):8-13. https://www.revcolanest.com.co/index.php/rca/article/view/785.