Kumari, S., J. Roychowdhury, and S. Biswas. “Prediction of Early Pregnancy Failure by Use of First Trimester Ultrasound Screening”. International Journal of Reproduction, Contraception, Obstetrics and Gynecology, vol. 5, no. 7, Feb. 2017, pp. 2135-40, doi:10.18203/2320-1770.ijrcog20161897.