Mananni, C., K. Sudarma, and H. Pramusinto. “PENINGKATAN HASIL BELAJAR MELAKUKAN SURAT MENYURAT MELALUI STUDENT TEAMS ACHIEVEMENT DIVISON”. Economic Education Analysis Journal, Vol. 1, no. 1, 1, https://journal.unnes.ac.id/sju/eeaj/article/view/551.