Sianipar, R.S. , Sijabat, D. and Simanjuntak, B. 2026. The Effect of Problem-Based Learning (PBL) on the Critical Thinking Skills of Fourth Grade Students. Jurnal Ilmu Sosial dan Humaniora . 4, 1 (Jan. 2026), 359–368. DOI:https://doi.org/10.58540/isihumor.v4i1.1495.