Harahap, N. H. and Lubis, M. S. (2026) “Development of Student Worksheets (LKPD) on Integer Topics to Improve Seventh-Grade Students’ Mathematical Problem Solving Abilities at SMP Negeri 3 Halongonan”, Mathline : Jurnal Matematika dan Pendidikan Matematika, 11(1), pp. 91–106. doi: 10.31943/mathline.v11i1.1105.