Wongkrajang, P., W. Chinswangwatanakul, P. Tientadakul, and N. Opartkiattikul. “Whole Blood Clotting Time: Variation of Practice in Coagulation Laboratory, Members of Thailand National External Quality Assessment Scheme”. Siriraj Medical Journal, vol. 63, no. 3, Apr. 2020, pp. 81-84, https://he02.tci-thaijo.org/index.php/sirirajmedj/article/view/240915.