Siagian, R. P. ., A. F. . Siagian, and D. . Sijabat. “The Influence of the Problem Based Learning (PBL) Learning Model on the Critical Thinking Skills of Grade V”. Jurnal Ilmu Sosial Dan Humaniora , vol. 4, no. 1, Jan. 2026, pp. 347-58, doi:10.58540/isihumor.v4i1.1491.