Hirunwong, P. . “A Development of CBC Quality Control System by Application of Sigma Metric in OPD Laboratory at Queen Savang Vadhana Memorial Hospital”. HCU Journal, vol. 25, no. 1, June 2021, pp. 53-62, https://he01.tci-thaijo.org/index.php/HCUJOURNAL/article/view/241479.