Deborah A. Dahl. <a href="http://www.w3.org/TR/2000/WD-nl-spec-20001120"><cite>Natural Language Semantics Markup Language for the Speech Interface Framework.</cite></a> 20 November 2000. W3C Working Draft. (Work in progress.) URL: <a href="http://www.w3.org/TR/2000/WD-nl-spec-20001120">http://www.w3.org/TR/2000/WD-nl-spec-20001120</a>