[css-variables] Regen with updated biblio.

Author: tabatkins

css-variables/Overview.html

@@ -840,7 +840,7 @@ <h3 class="no-num no-ref heading settled heading" id=normative><span class=conte
 
 <h3 class="no-num no-ref heading settled heading" id=informative><span class=content>
 Informative References</span><a class=self-link href=#informative></a></h3>
-<div data-fill-with=informative-references><dl><dt id=cssom title=CSSOM><a class=self-link href=#cssom></a>[CSSOM]<dd>Anne van Kesteren. <a href=http://www.w3.org/TR/2011/WD-cssom-20110712/>CSSOM</a>. 12 July 2011. W3C Working Draft. (Work in progress.) URL: <a href=http://www.w3.org/TR/2011/WD-cssom-20110712/>http://www.w3.org/TR/2011/WD-cssom-20110712/</a></dl></div>
+<div data-fill-with=informative-references><dl><dt id=css-extensions title=CSS-EXTENSIONS><a class=self-link href=#css-extensions></a>[CSS-EXTENSIONS]<dd>Tab Atkins Jr.. <a href=http://dev.w3.org/csswg/css-extensions/>CSS Extensions</a>. W3C Editor's Draft. (Work in progress.) URL: <a href=http://dev.w3.org/csswg/css-extensions/>http://dev.w3.org/csswg/css-extensions/</a><dt id=cssom title=CSSOM><a class=self-link href=#cssom></a>[CSSOM]<dd>Anne van Kesteren. <a href=http://www.w3.org/TR/2011/WD-cssom-20110712/>CSSOM</a>. 12 July 2011. W3C Working Draft. (Work in progress.) URL: <a href=http://www.w3.org/TR/2011/WD-cssom-20110712/>http://www.w3.org/TR/2011/WD-cssom-20110712/</a></dl></div>
 
 <h2 class="no-num no-ref heading settled heading" id=index><span class=content>
 Index</span><a class=self-link href=#index></a></h2>