Ayufauziyah N, Utami AD, Suwarman RF. Effectiveness of Math Universe on Students’ Combinatorics Understanding for Mathematics Olympiad Preparation. JPE [Internet]. 2026 Jan. 2 [cited 2026 Feb. 5];13(1):313-26. Available from: http://ejurnal.ikippgribojonegoro.ac.id/index.php/JPE/article/view/5270