Hamidah Sari Batubara, R. S. Wahyuni, and A. Andriani. “The Relationship Between Smartphone Usage and Student Achievement at SMP 21 Pekanbaru”. International Journal of Public Health Excellence (IJPHE), vol. 4, no. 1, July 2024, pp. 064-9, doi:10.55299/ijphe.v4i1.917.