Liebnis V, Indra Perdana, Elanneri Karani. Expediencies of Duolingo in English Language Learning: A Systematic Literature Review. EJI [Internet]. 2025 Jul. 13 [cited 2025 Jul. 17];9(2):453-62. Available from: https://ejournal-fkip.unisi.ac.id/eji/article/view/2997