Kevin Martin, Natalina Purba and Lisbet Novianti Sihombing 2023. Effect of Problem Based Learning on Student Learning Outcomes on Theme 2 Clean Air for Health Subtheme 1 the Body’s Way of Processing Clean Air Class V SD Negeri 4 Suhutnihuta Pardomuan. Indonesian Journal of Advanced Research. 2, 11 (Nov. 2023), 1465–1476. DOI:https://doi.org/10.55927/ijar.v2i11.6616.