Yuliana, S. Y., and N. B. Panjaitan. “A Comparison Between Games And Grammar Translation Methods In Improving Pupils’ Vocabulary Achievement”. Journal of International Scholars Conference - EDUCATION/SOCIAL SCIENCES, vol. 1, no. 2, Jan. 2016, pp. 225-8, https://jurnal.unai.edu/index.php/jiscedu/article/view/300.