Azzahra, Sekar, Jelly Prima Krisnawati Silaban, and Tengku Silvana Sinar. “Text Complexity in Digital Language Learning: Analyzing the Readability and Lexical Density of Duolingo’s Guidance Textbook”. Lexeme : Journal of Linguistics and Applied Linguistics 7, no. 1 (December 21, 2024): 29–36. Accessed April 9, 2025. https://openjournal.unpam.ac.id/index.php/LJLAL/article/view/44985.