Bohra, D., S. N., and S. M. S. “Serum Placental Growth Factor Levels and Uterine Artery Pulsatility Index at 11-13+6 Weeks Gestation As Early Predictors of Pre-Eclampsia: Prospective Observational Study”. International Journal of Reproduction, Contraception, Obstetrics and Gynecology, vol. 13, no. 2, Jan. 2024, pp. 364-9, doi:10.18203/2320-1770.ijrcog20240135.