Limpanyalert, Piyawan, and Saknan Manotaya. 2001. “Standard Curve of Symphysial-Fundal Height Measurement and Pregnancy Characteristics in Pregnant Women at King Chulalongkorn Memorial Hospital”. Thai Journal of Obstetrics and Gynaecology 13 (4). Bangkok, Thailand:197-206. https://he02.tci-thaijo.org/index.php/tjog/article/view/256647.