Ratnasari, Dwi, Kamirsyah Wahyu, and Sofyan Mahfudy. “Teachers’ Old-Fashioned Classroom Practices: A Pitfall on the Use of Digital Technology in Mathematics Teachings”. Beta: Jurnal Tadris Matematika 11, no. 2 (December 31, 2018): 114-130. Accessed January 20, 2019. https://jurnalbeta.ac.id/index.php/betaJTM/article/view/233.