Malte Wedel; et al. <a href="http://www.w3.org/TR/2001/WD-xhtml-forms-req-20010404"><cite>XForms Requirements.</cite></a> 4 April 2001. W3C Working Draft. (Work in progress.) URL: <a href="http://www.w3.org/TR/2001/WD-xhtml-forms-req-20010404">http://www.w3.org/TR/2001/WD-xhtml-forms-req-20010404</a>