Suchartwatnachai, C., U. Theppisai, S. Preutthipan, M. Jirapinyo, C. Thanuntaseth, and A. Chittacharoen. “Endometrial Thickness in Asymptomatic Postmenopausal Women”. Thai Journal of Obstetrics and Gynaecology, vol. 9, no. 3, Sept. 1997, pp. 219-23, https://he02.tci-thaijo.org/index.php/tjog/article/view/257251.