1. Smartphone, Smartphone OS market share, Q1 2015. 2015. Available at http://www.idc.com/prodserv/smartphone-os-market-share.jsp.
2. Password security: a case history;Morris;Commun ACM,1979
3. Improving user authentication on mobile devices: a touchscreen graphical password;Chiang,2013
4. Biometrics: a tool for information security;Jain;IEEE Trans Inf Forensics Secur,2006
5. Behavioral biometrics for smartphone user authentication;Buriro,2017