Lutfiah, Lutfiah, Sudirman Sudirman, Endang Wahyuningrum, and Benilda María Cantillo-Rudas. 2026. “Cognitive Barriers and Universal Design for Learning Support in Understanding Number Concepts in Students With Intellectual Disabilities”. Polyhedron International Journal in Mathematics Education 4 (2):165-92. https://doi.org/10.59965/pijme.v4i2.319.