PURBA, RISMAWATI. PENINGKATAN AKTIVITAS BELAJAR EKONOMI SISWA MELALUI PENERAPAN MODEL PEMBELAJARAN KOOPERATIF TIPE GROUP INVESTIGATION DI KELAS X “ 2 SMA NEGERI 12 MEDAN. JURNAL HANDAYANI PGSD FIP UNIMED, [S. l.], v. 1, n. 2, 2014. DOI: 10.24114/jh.v1i2.1269. Disponível em: http://jurnal.unimed.ac.id/2012/index.php/handayani/article/view/1269. Acesso em: 29 apr. 2025.