MBBS, Bushra Ashraf. 2019. “Efficacy and Safety of Oral Nifedipine With or Without Vaginal Progesterone in the Management of Threatened Preterm Labor”. International Journal of Reproductive BioMedicine (IJRM) 17 (9), 629–636. https://doi.org/10.18502/ijrm.v17i9.5098.