Rulita Nurfaizana, Della. “Analysis of the Application of Drill and Practice: Improve Business Letter Writing Skills”. Jurnal Inspirasi Pendidikan 14, no. 1 (August 27, 2024): 30–39. Accessed November 25, 2024. http://ejournal.unikama.ac.id/index.php/jrnspirasi/article/view/10209.