1. Article 29 – Data Protection Working Party. Working Document on Biometrics, 2003. Available at http://ec.europa.eu/justice-home/fsj/privacy/docs/wpdocs/2003/wp80-en.pdf. Retrieved on May 24, 2008.
2. Banking Automation Bulletin. Equens perspective – biometrics answers call for fast, simple checkout, 2009. Available at http://www.equens.com/Images/Article/%20biometrics.pdf. Retrieved on October 2009.
3. BBC News. Plastic card fraud goes back up (March 2008). Available at http://news.bbc.co.uk/2/hi/business/7289856.stm. Retrieved on May 2, 2011.
4. Berkman, O., and Ostrovsky, O. M. The unbearable lightness of PIN cracking. In Proceedings of the 11th International Conference on Financial Cryptography and 1st International Conference on Usable Security, FC’07/USEC’07, Berlin, Heidelberg, 2007, Springer-Verlag, 224–238. ISBN: 3-540-77365-7, 978-3-540-77365-8. Available at http://portal.acm.org/citation.cfm?id=1785594.1785622.
5. Bhatla, T. P., Prabhu, V., and Dua, A. Understanding credit card frauds, June 2003. Available at http://www.popcenter.org/problems/credit/_card/_fraud/PDFs/Bhatla.pdf. Retrieved on August 17, 2009.