Rugpao, Sungwal, Theera Tongsong, Theera Lao-kul-dilok, Jarunee Lao-kul-dilok, and Ratanaporn Sekhornrit. 1990. “Interrelationship Between Serum Iron Concentra tion and Pregnancy-induced Hypertension and Chronic Hypertension in Pregnancy”. Thai Journal of Obstetrics and Gynaecology 2 (2). Bangkok, Thailand:59-65. https://he02.tci-thaijo.org/index.php/tjog/article/view/257883.