Sudirman, Sudirman, dan Bambang Avip Priatna Martadiputra. 2020. “Exploratory Case Study Difficulty of Junior High School Students in Resolving Problems of the Pyramids Surface Area”. Math Didactic: Jurnal Pendidikan Matematika 6 (3), 277-86. https://doi.org/10.33654/math.v6i3.1131.