Ramadhania, D., S. . Prayitno, S. . Subarinah, and A. Arjudin. “Analysis of Mathematics Problem-Solving Ability on Plane Figure Subject Based on Van Hieles Theory at Junior High School”. Jurnal Pijar Mipa, vol. 17, no. 4, July 2022, pp. 493-8, doi:10.29303/jpm.v17i4.3413.