Situmorang, Komilie. “Improving the Academic English Achievement through Developing Students’ Self-Efficacy of Verbal Persuasions; A Classroom Action Research”. Journal of Languages and Language Teaching 10, no. 3 (July 25, 2022): 403–413. Accessed August 15, 2025. https://e-journal3.undikma.ac.id/index.php/jollt/article/view/5534.