Arias Lazarte, Silvia E., Celina H. Montes Ruiz, and Gladys C. Arias Lazarte. 2010. “Costs of Epidural Analgesia for Delivery. Instituto Nacional Materno Perinatal, January 2006”. ACTA MEDICA PERUANA 27 (1), 22-28. http://54.39.98.165/index.php/AMP/article/view/1458.