P. A. Awoyesuku and D. A. Mac Pepple, “Predictors of poor maternal and perinatal outcome among singleton maternal delivery referral cases to the obstetrics unit of a tertiary health facility in Port Harcourt, Nigeria”, Int J Reprod Contracept Obstet Gynecol, vol. 8, no. 11, pp. 4479–4484, Oct. 2019.