Saragih, Doni Irawan, and Edy Surya. “Analysis the Effectiveness of Mathematics Learning Using Contextual Learning Model”. International Journal of Sciences: Basic and Applied Research (IJSBAR) 34, no. 1 (June 14, 2017): 135–143. Accessed April 29, 2024. https://www.gssrr.org/index.php/JournalOfBasicAndApplied/article/view/7494.