Wahyuningrum, Ayunda Sri, et al. “Students’ Prior Knowledge As an Ontogenic Obstacle on the Topic of Ratio and Proportion”. Jurnal Pendidikan Matematika, vol. 17, no. 1, Oct. 2024, pp. 55-68, https://jpm.ejournal.unsri.ac.id/index.php/jpm/article/view/180.