Masayasu Ishikawa; Shane McCarron. <a href="http://www.w3.org/TR/2007/WD-xhtml11-20070216"><cite>XHTML&#8482; 1.1 - Module-based XHTML - Second Edition.</cite></a> 16 February 2007. W3C Working Draft. (Work in progress.) URL: <a href="http://www.w3.org/TR/2007/WD-xhtml11-20070216">http://www.w3.org/TR/2007/WD-xhtml11-20070216</a>