1. B. Santoso, Linier Journal Math Education 1 (1), 57–63 (2020).
2. U. D’Ambriso, Learn Math. 5 (1), 44–8 (1985).
3. D. A. Kusuma, S. P. Dewanto, and B. T. Nurani, Journal of Physics: Conference Series, pp. 1–8 (2016)
4. Risdiyanti and R. C. I. Prahmana, Journal of Physics: Conference Series. pp. 1–6 (2017).
5. M. Zayyadi and A. Subaidi, Jurnal Sigma 2 (2), 1–4 (2017).