Sulastri, Y.L. and Ahmatika, D. 2020. Analisis Keterampilan Abad 21 Melalui Model Problem Based Calculus Learning Berbantuan Geogebra. SJME (Supremum Journal of Mathematics Education). 4, 1 (Jan. 2020), 42–54. DOI:https://doi.org/10.35706/sjme.v4i1.2254.