Abdullah, A. H. and Shin, B. (2019) “A comparative study of quadrilaterals topic content in mathematics textbooks between Malaysia and South Korea”, Journal on Mathematics Education, 10(3), pp. 315–340. Available at: https://jme.ejournal.unsri.ac.id/index.php/jme/article/view/3797 (Accessed: 29 July 2025).