Soesanto, Robert Harry. “A REVIEW OF STUDENT ERROR ANALYSIS IN LINEAR ALGEBRA COURSE BASED ON KASTOLAN STAGE MODEL”. De Fermat : Jurnal Pendidikan Matematika 4, no. 1 (June 30, 2021): 1–12. Accessed January 18, 2022. https://jurnal.pmat.uniba-bpn.ac.id/index.php/DEFERMAT/article/view/147.