., Ambalegin; SURYANI, M S. Mother Tongue Affecting the English Vowel Pronounciation of Batak Toba Adults. KnE Social Sciences, [S. l.], v. 3, n. 4, p. 78–86, 2018. DOI: 10.18502/kss.v3i4.1920. Disponível em: https://knepublishing.com/index.php/KnE-Social/article/view/1920. Acesso em: 30 aug. 2025.