Silviana, N., Siburian, G., Sijabat, F. S., & Hutajulu, G. P. (2026). The Effect of Using Duolingo Application on The Students’ Vocabulary Improvement of German Language at A1 Level. DEIKTIS: Jurnal Pendidikan, Bahasa Dan Sastra, 6(2), 2392-2397. https://doi.org/10.53769/deiktis.v6i2.3362