Kumari, S., and G. Chaudhary. “Correlation of Levels of Early Second Trimester Beta-Human Chorionic Gonadotropin Levels With Severity of Preeclampsia”. International Journal of Reproduction, Contraception, Obstetrics and Gynecology, vol. 11, no. 12, Nov. 2022, pp. 3340-5, doi:10.18203/2320-1770.ijrcog20223127.