Novita, Willy, dkk. “THE DIFFERENCE OF STUDENT ACHIEVEMENT USING MODEL PROBLEM BASED LEARNING MODEL WITH PROJECT BASED LEARNING MODEL MUSHROOMS MATERIALS IN CLASS X SMA NEGERI 16 MEDAN”. Jurnal Pelita Pendidikan, vol. 4, no. 4, Desember 2016, doi:10.24114/jpp.v4i4.8639.