Br. Ginting, Elvita Ersama, Sabaruddin Yunis Bangun, and Samsuddin Siregar. 2024. “Development of a Digital App-Based Sambo Sports Book for Students at High School Level Extracurricular Activities”. Jurnal SPORTIF : Jurnal Penelitian Pembelajaran 10 (2):320-34. https://doi.org/10.29407/js_unpgri.v10i2.23102.