pumpa , S., and K. Sirisabhabhorn. “The comparison study of urine specific gravity measuring by refractive analyzers for diagnose kidney diseases”. Thammasat University Hospital Journal Online, vol. 7, no. 3, Dec. 2022, pp. 77-82, https://he02.tci-thaijo.org/index.php/TUHJ/article/view/260569.