Wahyuni, Reni, Tatang Herman, and Siti Fatimah. “Letters in Algebra As The Transition from Arithmetic Thinking to Algebraic Thinking”. Mosharafa: Jurnal Pendidikan Matematika 12, no. 3 (July 30, 2023): 441–452. Accessed October 7, 2024. https://journal.institutpendidikan.ac.id/index.php/mosharafa/article/view/818.