Saleh Gargari, Soraya, Zahra Seify, Ladan Haghighi, Maryam Khoshnood Shariati, and Masoumeh Mirzamoradi. “Risk Factors and Consequent Outcomes of Placenta Previa: Report From a Referral Center”. Acta Medica Iranica 54, no. 11 (December 14, 2016): 713-717. Accessed December 5, 2020. https://acta.tums.ac.ir/index.php/acta/article/view/6060.