Asmus Freytag; Martin D&#252;rst. <a href="http://www.w3.org/TR/2007/NOTE-unicode-xml-20070516"><cite>Unicode in XML and other Markup Languages.</cite></a> 16 May 2007. W3C Note. URL: <a href="http://www.w3.org/TR/2007/NOTE-unicode-xml-20070516">http://www.w3.org/TR/2007/NOTE-unicode-xml-20070516</a>