Wiruchpongsanon, P., & Maharungruengrat, A. (2013). Incidence of Obstetric Anal Sphincter Injuries by 60 Degrees for the Incision Angle of Mediolateral Episiotomy before Delivery. Thai Journal of Obstetrics and Gynaecology, 21(3), 95–100. retrieved from https://he02.tci-thaijo.org/index.php/tjog/article/view/7231