Nst, Masringgit Marwiyah, et al. “THE DIFFERENCE PROBLEM SOLVING SKILLS OF PHYSICS WHO ARE TAUGHT USING THE PROJECT BASED LEARNING MODEL WITH PROBLEM BASED LEARNING”. Jurnal Pendidikan Fisika, vol. 9, no. 2, Dec. 2020, pp. 68-72, doi:10.22611/jpf.v9i2.14061.