Susanti, R., S. ., D. ., and M. Rohmadi. “Politeness Principles and Strategies in Language Used By President Joko Widodo to Indonesian Citizens, Through Vlog #JOKOWIMENJAWAB”. KnE Social Sciences, Vol. 3, no. 9, July 2018, pp. 798–806, doi:10.18502/kss.v3i9.2744.