Tongsong, Theera, Chanane Wanapirak, and Acharawan Yampochai. “Ultrasonic Measurements of Fetal Biparietal Diameter in Normal Pregnant Northern Thai Women”. Thai Journal of Obstetrics and Gynaecology 2, no. 2 (July 1, 1990): 73–79. accessed September 28, 2026. https://he02.tci-thaijo.org/index.php/tjog/article/view/257885.