Yanti, S., A. Tjalla, A. Sutisna, and T. W. Ramdhan. “Constructing an instrument to measure and evaluate problem-solving skills in elementary school students: A focus on mathematical word problem-solving”. Kasetsart Journal of Social Sciences, vol. 47, no. 1, Mar. 2026, p. 470113, https://so04.tci-thaijo.org/index.php/kjss/article/view/287923.