“Effect of Spinal Anesthesia With Sufentanil on Length of Stages I and II of Labor in Singleton Pregnant Women: A Randomized Controlled Trial”. Universa Medicina 42, no. 1 (April 17, 2023): 94–100. Accessed April 30, 2025. https://www.univmed.org/ejurnal/index.php/medicina/article/view/1430.