Silprasert, S., C. Phaloprakarn, S. Manusirivithaya, and B. Wiriyasirivaj. “A six-hour urinary protein-creatinine ratio for predicting significant proteinuria in preeclampsia”. Thai Journal of Obstetrics and Gynaecology, vol. 17, no. 1, Jan. 2009, pp. 30-36, https://he02.tci-thaijo.org/index.php/tjog/article/view/7671.