Siregar, Ivan Michael. “Pengembangan Attendance System Berbasis Android”. SISINFO : Jurnal Sistem Informasi dan Informatika 2, no. 1 (February 28, 2020): 48–54. Accessed February 14, 2026. https://jurnalunibi.unibi.ac.id/ojs/index.php/SisInfo/article/view/250.