Siswanto, H., and Y. Astutik. “Duolingo Application and Vocabulary Scores of Seventh Graders: Pencapaian Aplikasi Duolingo Dan Skor Kosakata Siswa Kelas 7”. Academia Open, vol. 10, no. 1, Feb. 2026, p. 10.21070/acopen.10.2025.12475, doi:10.21070/acopen.10.2025.12475.