Archana, R., and S. Patra. “Diagnostic Accuracy of Sacral Rhomboid Dimensions in Prediction of Cephalopelvic Disproportion in Primigravidae”. International Journal of Reproduction, Contraception, Obstetrics and Gynecology, vol. 10, no. 4, Mar. 2021, pp. 1472-7, doi:10.18203/2320-1770.ijrcog20211123.