Siahaan DG, Nahak MHKI, Bouk E. Duolingo Application as A Mean to Deepen Understanding of English Vocabulary by Students of English Educational Department Timor University. Poltanesa [Internet]. 2024 Dec. 6 [cited 2025 Jan. 6];25(2):208-16. Available from: https://e-journal.politanisamarinda.ac.id/index.php/tanesa/article/view/3189