Mao, Mao, Zhaohui Wang, Caijuan Li, Nan Wang, Shanwu Feng, Shiqin Xu, Xiaofeng Shen, and Xian Wang. 2017. “Effectiveness of A Single Dose of Epidural Morphine for Postpartum Perineal Pain: A Randomized Controlled Trial”. Science Insights 2017 (5):1-6. https://doi.org/10.15354/si.17.ar062.