SUMBAYAK, D. M. The Diphthongs: The Obstacles for Indonesian Speakers of English. Lingua Cultura, [S. l.], v. 3, n. 2, p. 107 - 115, 2009. DOI: 10.21512/lc.v3i2.337. Disponível em: https://journal.binus.ac.id/index.php/Lingua/article/view/337. Acesso em: 25 mar. 2025.