T. R. Pinnington, J. Arthan, C. Komoltri, and P. Chanprapaph, “Accuracy of the Combined First Trimester Down Syndrome Screening Test and the Optimum Range of the Cut-off Point for Intermediate-risk Identification: Twelve years’ experience ”, Thai J Obstet Gynaecol, vol. 32, no. 4, pp. 269–277, Jul. 2024.