Rizki Nurhidayah Sitompul. “Duolingo in Basic English Learning: Student Engagement and Achievement”. Jurnal Pendidikan dan Sastra Inggris 5, no. 3 (December 15, 2025): 563–569. Accessed February 4, 2026. https://journalshub.org/index.php/JUPENSI/article/view/6321.