Yen, C. C., and N. M. Tajudin. “Assessing First Year Pre-Service Teachers’ Geometric Reasoning Ability on Two-Dimensional Shapes (1 - 12)”. EDUCATUM Journal of Science, Mathematics and Technology, vol. 2, no. 1, June 2015, pp. 1-12, https://ojs.upsi.edu.my/index.php/EJSMT/article/view/24.