Merlin Hughes; John Boyer; Joseph Reagle. <a href="http://www.w3.org/TR/2002/REC-xmldsig-filter2-20021108/"><cite>XML-Signature XPath Filter 2.0.</cite></a> 8 November 2002. W3C Recommendation. URL: <a href="http://www.w3.org/TR/2002/REC-xmldsig-filter2-20021108/">http://www.w3.org/TR/2002/REC-xmldsig-filter2-20021108/</a>