Silaban, Harjon. “English Teaching Learning by Leveling System Model on Class XI of Vocational High School 3 Samarinda Students”. Educationist: Journal of Educational and Cultural Studies 1, no. 2 (November 19, 2022): 234–241. Accessed May 14, 2026. https://jurnal.litnuspublisher.com/index.php/jecs/article/view/77.