Okta, D. O. F. “An Analysis of Politeness Strategies on Students Communications in Second Semester of English Education Department at Muhammadiyah Kotabumi University Academic Year 2021/2022”. Griya Cendikia, vol. 8, no. 1, Feb. 2023, pp. 187-9, https://juma.umko.ac.id/index.php/griya-cendikia/article/view/465.