Gonchik Tsymzhitov (2016). TWO-FACTOR AUTHENTICATION SYSTEM. SGEM International Multidisciplinary Scientific GeoConference EXPO Proceedings; 16th International Multidisciplinary Scientific GeoConference SGEM2016, Informatics, Geoinformatics and Remote Sensing. https://doi.org/10.5593/sgem2016/b21/s07.064