Adnan, M., and E. Zakaria. “Conceptual Knowledge Of Fractions Among Pre-Service Mathematics Teachers (12 - 22)”. Jurnal Pendidikan Sains Dan Matematik Malaysia, vol. 2, no. 1, May 2012, pp. `12-22, https://ojs.upsi.edu.my/index.php/JPSMM/article/view/1812.