Hasibuan, A. A., and M. N. S. Rangkuti. “The Effect of the Problem Based Learning Model on Students’ Communication Skills and Learning Outcomes in Ecosystem Material”. Biocaster : Jurnal Kajian Biologi, vol. 6, no. 3, July 2026, pp. 1651-60, doi:10.36312/biocaster.v6i3.1176.