Phromboot, T., A. Chittacharoen, and S. Pitakkijronnakorn. “Efficacy of intraumbilical vein Methylergonovine maleate on duration of third stage of labor”. Thai Journal of Obstetrics and Gynaecology, vol. 20, no. 1, May 2012, pp. 29-33, https://he02.tci-thaijo.org/index.php/tjog/article/view/1153.