-, Wulansari. The Most Difficult Vowel Sound Pronunciation among Three Different Semester Students at UIN Sunan Ampel Surabaya: An Acoustic Analysis. Tell : Teaching of English Language and Literature Journal, [S. l.], v. 8, n. 1, p. 53–62, 2020. DOI: 10.30651/tell.v8i1.4408. Disponível em: https://journal.um-surabaya.ac.id/Tell/article/view/4408. Acesso em: 5 aug. 2024.