Adi Suarman Situmorang, and Enjelika Pandiangan. “Analysis Of Mathematical Communication Skills On The Material Of Two-Variable Linear Equation System In Smp Negeri 7 Medan”. International Journal Of Humanities Education and Social Sciences (IJHESS), vol. 2, no. 1, Aug. 2022, doi:10.55227/ijhess.v2i1.243.