Jim Barnett. <a href="http://www.w3.org/TR/2008/WD-mmi-arch-20081016"><cite>Multimodal Architecture and Interfaces.</cite></a> 16 October 2008. W3C Working Draft. (Work in progress.) URL: <a href="http://www.w3.org/TR/2008/WD-mmi-arch-20081016">http://www.w3.org/TR/2008/WD-mmi-arch-20081016</a>