Syamsuri, Syamsuri, Purwanto Purwanto, Subanji Subanji, and Santi Irawati. “Characterization of Students Formal-Proof Construction in Mathematics Learning”. Communications in Science and Technology 1, no. 2 (November 30, 2016). Accessed May 4, 2024. https://cst.kipmi.or.id/journal/article/view/2.