Ridwan, Ridwan. “Writing Description With The Model of Group Investigation”. Gramatika: Jurnal Ilmiah Kebahasaan dan Kesastraan 1, no. 1 (June 1, 2013): 63-74. Accessed April 26, 2024. http://gramatika.kemdikbud.go.id/index.php/gramatika/article/view/20.