Ruangchainikom, Wibool, and Saravut Sarapak. “Ultrasonographic Fetal Ear Measurement in Predicting Fetal Chromosome Abnormality”. Thai Journal of Obstetrics and Gynaecology 13, no. 3 (July 1, 2001): 147–150. accessed September 29, 2026. https://he02.tci-thaijo.org/index.php/tjog/article/view/256529.