Phithakwatchara, Nisarat, and Chayawat Phatihattakorn. 2020. “Specificity of Hypocoiled Umbilical Cord in Prediction of Fetal Trisomy 21 in the Second Trimester”. Siriraj Medical Journal 62 (4):170-72. https://he02.tci-thaijo.org/index.php/sirirajmedj/article/view/243895.