Saputra, D. D., and A. R. Tanaamah. “Optimizing the Use of QR Codes in Web-Based Attendance Information Systems During the Covid-19 Pandemic (Case Study: KONI Salatiga City)”. Jurnal Mantik, vol. 5, no. 2, Aug. 2021, pp. 1076-8, doi:10.35335/jurnalmantik.Vol5.2021.1461.pp1076-1086.