Rizk, A., and E. Mosbah. “Occurrence and Surgical Reconstruction of Perineal Lacerations and Rectovaginal Fistulae in Dairy Cows”. Journal of Advanced Veterinary Research, vol. 6, no. 4, Oct. 2016, pp. 123-9, https://advetresearch.com/index.php/AVR/article/view/18.