Jim Allan; Jan Richards. <a href="http://www.w3.org/TR/2007/WD-UAAG20-requirements-20071031"><cite>User Agent Accessibility Guidelines 2.0 Requirements.</cite></a> 31 October 2007. W3C Working Draft. (Work in progress.) URL: <a href="http://www.w3.org/TR/2007/WD-UAAG20-requirements-20071031">http://www.w3.org/TR/2007/WD-UAAG20-requirements-20071031</a>