1. Schneier, B.: Real-World Passwords. Crypto-Gram Newsletter (December 15, 2006)
2. Magalhaes, S.T., Revett, K., Santos, H.D.: Generation of Authentication Strings From Graphic Keys. International Journal of Computer Science and Network Security 6(3B), 240–246 (2006)
3. Brown, A.S., Bracken, E., Zoccoli, S., Douglas, K.: Generating and remembering passwords. Applied Cognitive Psychology 18, 641–651 (2004)
4. Carstens, D.S., McCauley-Bell, P., Malone, L.C., DeMara, R.F.: Evaluation of the Human Impact of Password Authentication Practices on Information Security. Informing Science Journal 7, 67–85 (2004)
5. Zviran, M., Haga, W.J.: User authentication by cognitive passwords: an empirical assessment. JCIT 5, 137–144 (1990)