A. Lorien and T. Wellem, “Implementasi Sistem Otentikasi Dokumen Berbasis Quick Response (QR) Code dan Digital Signature”, J. RESTI (Rekayasa Sist. Teknol. Inf.) , vol. 5, no. 4, pp. 663–671, Aug. 2021, doi: 10.29207/resti.v5i4.3316.