Daniel C. Burnett. <a href="http://www.w3.org/TR/2000/WD-reusable-dialog-reqs-20000426"><cite>Reusable Dialog Requirements for Voice Markup Language.</cite></a> 26 April 2000. W3C Working Draft. (Work in progress.) URL: <a href="http://www.w3.org/TR/2000/WD-reusable-dialog-reqs-20000426">http://www.w3.org/TR/2000/WD-reusable-dialog-reqs-20000426</a>