Wongtiraporn, W. ., N. . Opartkiattikul, and P. . Tientadakul. “The Value of Local ISI Calibration in Correcting the Variability in INR Determination”. Siriraj Medical Journal, vol. 55, no. 7, July 2003, pp. 381-4, https://he02.tci-thaijo.org/index.php/sirirajmedj/article/view/245416.