Kurniawan, Ferdinan, Margareta Rosvita, and Rintya Yuniastari. “An Acoustic Study on English Vowels Produced by Indonesian Speakers: Exploring Determining Factors and Contact Situations”. k@ta: A Biannual Publication on the Study of Languange and Literature 26, no. 1 (June 19, 2024): 49-61. Accessed November 3, 2024. https://kata.petra.ac.id/index.php/ing/article/view/19662.