Bonar Siagian, and M Bambang Purwanto. “Lextutor English Learning Pronunciation and Vocabulary: A Language Data Base Program ”. PUSTAKA: Jurnal Bahasa dan Pendidikan 4, no. 1 (December 4, 2023): 116–130. Accessed July 3, 2024. https://jurnal-stiepari.ac.id/index.php/pustaka/article/view/1062.