Musthofa, S., Prasetyo, K. and Purnomo, N.H. 2019. Problem-Based Learning Effects on Students Learning Outcomes in the Themes of The Potential and Utilization of Natural Resources. The Indonesian Journal of Social Studies. 2, 2 (Nov. 2019), 95–101. DOI:https://doi.org/10.26740/ijss.v2n2.p95-101.