SIMANJUNTAK, Mila Kamelia; NAPITUPULU, Fenty Debora; SIAHAAN, Sahat Taruli. The Effect Of Duolingo Application In Learning English Vocabulary At First Grade Of SMP Nusantara Lubuk Pakam. Innovative: Journal Of Social Science Research, [S. l.], v. 3, n. 5, p. 831–838, 2023. Disponível em: https://j-innovative.org/index.php/Innovative/article/view/4928. Acesso em: 18 aug. 2026.