Annisa Sevia Putri, Melinda Nata Sari, Rizka Dwi Fani, Sylfana Ryan Mulia, and Supriadi, “Analysis of Vowel Pronunciation Errors of Grade IX Students of MTs Harapan Jasa Langkat”, JoAL, vol. 2, no. 2, pp. 36–40, Jan. 2023.