P. A. Awoyesuku, D. H. John, and B. O. Altraide, “Prevalence and predictors of episiotomy and perineal tear at a tertiary hospital in Port-Harcourt, Nigeria”, Int J Reprod Contracept Obstet Gynecol, vol. 9, no. 11, pp. 4595–4600, Oct. 2020.