INFUSING A GAMIFICATION MECHANISM THROUGH DUOLINGO FOR ENGLISH SPEAKING PROFICIENCY: PERCEPTIONS OF THE INDONESIAN EFL INSTRUCTOR AND STUDENTS. Konstruktivisme : Jurnal Pendidikan dan Pembelajaran, [S. l.], v. 12, n. 1, p. 69–80, 2020. DOI: 10.35457/konstruk.v12i1.894. Disponível em: https://ejournal.unisbablitar.ac.id/index.php/konstruktivisme/article/view/894. Acesso em: 7 jan. 2026.