Abbasi, A. M., A. . Ali Arain, S. . Khokhar, and M. . Batool. “An Instrumental Study of Speech Variability of English Back-Rounded Vowels Between the English & Karachiites Pinglish: Acoustics of English Back-Rounded Vowels”. Pakistan Journal of Languages and Translation Studies, vol. 10, no. 2, Dec. 2022, pp. 40-60, https://pjlts.uog.edu.pk/index.php/pjlts/article/view/49.