Marlinda, Sheli, and Kiki Nia Sania Effendi. “Students’ Epistemological Obstacle in Solving Problems on the Subject of Quadratic Equations”. Radian Journal: Research and Review in Mathematics Education, vol. 2, no. 4, Aug. 2024, pp. 151-65, doi:10.35706/rjrrme.v2i4.12091.