Ginting, Heryansyah, and Edy Surya. “Development Learning Device Based for Measuring Contextual Critical Thinking Skills Students SD Class VI Mathematical”. International Journal of Sciences: Basic and Applied Research (IJSBAR) 33, no. 3 (June 8, 2017): 301–310. Accessed May 2, 2024. https://www.gssrr.org/index.php/JournalOfBasicAndApplied/article/view/7544.