Vebianti, Fina, Sunardi Sunardi, Abi Suwito, Dinawati Trapsilasiwi, and Ervin Oktavianingtyas. “Analysis of Geometry Problem Solving Based on APOS Theory for Class IX Students”. Journal of Education and Learning Mathematics Research (JELMaR) 3, no. 1 (June 20, 2022): 33-41. Accessed December 4, 2024. https://jelmar.wisnuwardhana.ac.id/index.php/jelmar/article/view/69.