1. K. Barry. Counterfeits and Counterfeiters: The Ancient World. Available on-line at: http://www.ancient-times.com/newsletters/n13/n13.html K. Barry. Counterfeits and Counterfeiters: The Ancient World. Available on-line at: http://www.ancient-times.com/newsletters/n13/n13.html
2. ANSI X9.62-1998. Public Key Cryptography for the Financial Services Industry: The Elliptic Curve Digital Signature Algorithm (ECDSA) 1998. On-line at: http://www.x9.org. ANSI X9.62-1998. Public Key Cryptography for the Financial Services Industry: The Elliptic Curve Digital Signature Algorithm (ECDSA) 1998. On-line at: http://www.x9.org.
3. D. W. Bauder. Personal Communication. D. W. Bauder. Personal Communication.
4. D. W. Bauder. An Anti-Counterfeiting Concept for Currency Systems. Research report PTK- 11990. Sandia National Labs. Albuquerque NM 1983. D. W. Bauder. An Anti-Counterfeiting Concept for Currency Systems. Research report PTK- 11990. Sandia National Labs. Albuquerque NM 1983.