Juul, Leonard, and Gerhard B. Theron. “Risk Factors for Third- and Fourth-Degree Perineal Tears During Vaginal Delivery”. Urogynaecologia 25, no. 1 (July 18, 2011): e2. Accessed May 9, 2024. https://www.urogynaecologia.org/uij/article/view/uij.2011.e2.