Sulastri, Yayu Laila, and Deti Ahmatika. 2020. “Analisis Keterampilan Abad 21 Melalui Model Problem Based Calculus Learning Berbantuan Geogebra”. SJME (Supremum Journal of Mathematics Education) 4 (1):42-54. https://doi.org/10.35706/sjme.v4i1.2254.