Costa-Martins, J. M., Dias, C. C., Pereira, M., & Tavares, J. (2015). Effects of Local Anesthetic on the Time Between Analgesic Boluses and the Duration of Labor in Patient-Controlled Epidural Analgesia: Prospective Study of Two Ultra-Low Dose Regimens of Ropivacaine and Sufentanil. Acta Médica Portuguesa, 28(1), 70–76. https://doi.org/10.20344/amp.5708