“The Relationship Between Self-Concept and Academic Procrastination in Al-Washliyah 3 High School Students in Medan”. Jurnal Ilmiah Mandala Education 11, no. 1 (January 5, 2025): 74–83. Accessed September 19, 2026. https://ejournal.mandalanursa.org/index.php/JIME/article/view/8139.