SAUSAN SABILA; AFRAHUL FADHILLAH PARINDURI; DEDY SUHERY; RAHMADSYAH RANGKUTI. Contrastive Analysis English Vowel Produced By Mandailing Speakers. Atmosfer: Jurnal Pendidikan, Bahasa, Sastra, Seni, Budaya, dan Sosial Humaniora, [S. l.], v. 4, n. 3, p. 54–67, 2026. DOI: 10.59024/atmosfer.v4i3.1841. Disponível em: https://pbsi-upr.id/index.php/atmosfer/article/view/1841. Acesso em: 2 aug. 2026.