รัตนเสถียร ข., and อิ่มใจ เ. “ Quality Control Specimens and the Study of Quality Control Stage I for Assigning Chemical Constiuents of the Specimens”. Journal of Associated Medical Sciences, vol. 12, no. 2, June 2016, p. 79, https://he01.tci-thaijo.org/index.php/bulletinAMS/article/view/60911.