Hubungan asupan zink, kalsium dan sosial ekonomi keluarga dengan prestasi belajar siswa usia 13-15 tahun di SMP Nabil Husein Samarinda: The relationship between zinc and calcium intake and family socioeconomic status with academic achievement of 13-15 year old students at SMP Nabil Husein Samarinda. widyakesehatan [Internet]. 2023 May 12 [cited 2026 Sep. 21];5(1):41-9. Available from: https://ejournal.unhi.ac.id/index.php/widyakesehatan/article/view/4069