1. Honan, M.: Kill the password: Why a string of characters can’t protect us anymore. Wired (2012)
2. United States Department of Homeland Security: United States Computer Emergency Readiness Team (US-CERT). Security tip (ST04-002): Choosing and protecting passwords (2009), retrieved from website,
http://www.us-cert.gov/cas/tips/ST04-002.htm
3. Lecture Notes in Computer Science;B.C. Stanton,2014
4. Arif, A.S., Lopez, M.H., Stuerzlinger, W.: Two new mobile touchscreen text entry techniques. In: Poster at the 36th Graphics Interface Conference, pp. 22–23 (2010)
5. Nicolau, H., Jorge, J.: Elderly text-entry performance on touchscreens. In: Proceedings of the 14th International ACM SIGACCESS Conference on Computers and Accessibility. ACM, Boulder (2012)