KUNNO, R., C. RUANGVIRIYACHAI, and S. CHANTHAI. “Sample Preparation for Trace Analysis of Iron, Copper and Zinc in Thai Fruit Wines by ICP-AES”. Walailak Journal of Science and Technology (WJST), vol. 6, no. 2, Nov. 2011, pp. 243-54, https://wjst.wu.ac.th/index.php/wjst/article/view/64.