Umardiyah, Fitri, and Ninik Maslukhah. “Instruments of Communicative Skill According to 4C’s In Trigonometric Ratio”. APPLICATION: Applied science in Learning Research 1, no. 3 (February 5, 2022): 166–172. Accessed April 30, 2024. https://ejournal.unwaha.ac.id/index.php/application/article/view/1967.