Panggabean, L., and D. C. Simanjuntak. “Metacognitive Strategies To Enhance Students’ Listening Comprehension Ability”. Journal of International Scholars Conference - EDUCATION/SOCIAL SCIENCES, vol. 1, no. 2, Jan. 2016, pp. 161-73, https://jurnal.unai.edu/index.php/jiscedu/article/view/292.