D.  Eastlake, S. Crocker, J. Schiller. <a href="http://www.ietf.org/rfc/rfc4086.txt"><cite>Randomness Recommendations for Security.</cite></a>. IETF RFC 4086. June 2005. URL: <a href="http://www.ietf.org/rfc/rfc4086.txt">http://www.ietf.org/rfc/rfc4086.txt</a>