Kevin Smith; David Sanders. <a href="http://www.w3.org/TR/2007/NOTE-DDR-requirements-20071217"><cite>Device Description Repository Requirements 1.0.</cite></a> 17 December 2007. W3C Note. URL: <a href="http://www.w3.org/TR/2007/NOTE-DDR-requirements-20071217">http://www.w3.org/TR/2007/NOTE-DDR-requirements-20071217</a>