Br. Ginting, E. E. ., Bangun, S. Y. and Siregar, S. (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), pp. 320–334. doi: 10.29407/js_unpgri.v10i2.23102.