Roland Merrick; Rotan Hanrahan. <a href="http://www.w3.org/TR/2004/NOTE-di-atdi-20040218"><cite>Authoring Techniques for Device Independence.</cite></a> 18 February 2004. W3C Note. URL: <a href="http://www.w3.org/TR/2004/NOTE-di-atdi-20040218">http://www.w3.org/TR/2004/NOTE-di-atdi-20040218</a>