Hasibuan, S. J., T. R. B. Sipakkar, T. Helmira, M. F. N. Pardosi, and A. Anim. “Implementation of Problem Based Learning (PBL) Model to Increase Students’ Interest in Learning Spatial Building Material in Class VII of SMP Negeri 5 Kisaran”. Holistic Science, vol. 4, no. 3, Dec. 2024, pp. 483-7, doi:10.56495/hs.v4i3.663.