Kumar, N., V. Das, A. Agrawal, A. Pandey, and S. Agrawal. “Association of Serum Placental Growth Factor and Pregnancy Associated Plasma Protein A Between 11 to 14 Weeks and Pre-Eclampsia”. International Journal of Reproduction, Contraception, Obstetrics and Gynecology, vol. 10, no. 5, Apr. 2021, pp. 1925-30, doi:10.18203/2320-1770.ijrcog20211513.