Mufliharsi, Risa, and Heppy Atma Pratiwi. 2019. “POLITENESS PRINCIPLE: PRESIDENT JOKO WIDODO’S SPEECH ACT IN VIDEO BLOG”. Bahtera: Jurnal Pendidikan Bahasa Dan Sastra 18 (1), 79-92. https://doi.org/10.21009/BAHTERA.181.07.