“THE EFFECT OF USING DUOLINGO APPLICATION AS TEACHING MEDIA TO IMPROVE VOCABULARY MASTERY OF ELEVENTH GRADERS”. J-Shelves of Indragiri (JSI) 6, no. 2 (November 27, 2024): 19–33. Accessed October 9, 2025. https://ejournal-fkip.unisi.ac.id/shelves/article/view/2784.