Putri, D. P. M., and H. Supriyono. “Rancang Bangun Sistem Presensi Berbasis QR Code Menggunakan Framework Codeigniter (Studi Kasus Kehadiran Asisten Praktikum)”. Jurnal INSYPRO (Information System and Processing), Vol. 4, no. 1, May 2019, pp. 17-26, doi:10.24252/insypro.v4i1.6987.