Rancang Bangun Alat Metal Detector dengan Metode Beat Frequency Oscillator. Progressive Physics Journal, [S. l.], v. 3, n. 2, p. 191–199, 2022. DOI: 10.30872/ppj.v3i2.957. Disponível em: https://jurnal.fmipa.unmul.ac.id/index.php/ppj/article/view/957. Acesso em: 24 oct. 2025.