กีรติวิบูลย์ ว. Comparisons of Opinions between Students Unwithdrawn and Withdrawn Calculus 1 of Thaksin University. KKU Science Journal, [S. l.], v. 44, n. 1, p. 222–236, 2016. Disponível em: https://ph01.tci-thaijo.org/index.php/KKUSciJ/article/view/249492. Acesso em: 26 aug. 2026.