Thota Murni Gultom, and Hardi Tambunan. “Analysis Of Students ’ Understanding Of Mathematical Concepts In Class Viii Function Material Smp Negeri Satu Atap Tanjung Balai T.P 2021/2022”. International Journal Of Humanities Education and Social Sciences (IJHESS), vol. 2, no. 3, Dec. 2022, doi:10.55227/ijhess.v2i3.287.