HERNADIJAYA, Nadya Savira. The Use of Duolingo Application to Enhance English Vocabulary of Junior High School. RETAIN : Journal of Research in English Language Teaching, [S. l.], v. 8, n. 2, 2020. Disponível em: https://ejournal.unesa.ac.id/index.php/retain/article/view/33055. Acesso em: 29 jun. 2025.