Songthamwat, S. “Prevalence of Abnormal Prenatal Screening for Down Syndrome in Udonthani Hospital Using Nuchal Translucency and Biochemical Marker”. Srinagarind Medical Journal, vol. 23, no. 2, Nov. 2013, pp. 153-60, https://li01.tci-thaijo.org/index.php/SRIMEDJ/article/view/13066.