Dahsah, C., S. Sanguanruang, S. Sung-Ong, and N. Yutakom. “Grade 10 and 11 Thai Students’ Conceptions about Stoichiometry”. Kasetsart Journal of Social Sciences, vol. 27, no. 2, Dec. 2006, pp. 225-33, https://so04.tci-thaijo.org/index.php/kjss/article/view/246404.