Meiratnasari, Ayu, Agus Wijayanto, and Suparno Suparno. “An Analysis of Politeness Strategies in Indonesian English Textbooks”. ELS Journal on Interdisciplinary Studies in Humanities 2, no. 4 (December 16, 2019): 529–540. Accessed March 31, 2025. http://journal.unhas.ac.id/index.php/jish/article/view/8393.