[css3-content] Fixed broken biblio entry.

Author: bert-github

css-content/Overview.src.html

@@ -180,7 +180,7 @@ <h2>Pseudo-elements</h2>
 designers to refer to this otherwise inaccessible information.
 Pseudo-elements also provide style sheet designers a way to assign
 style to content that does not exist in the source document.
-Pseudo elements are defined in the [[SELECTORS]] specification.</p>
+Pseudo elements are defined in the [[SELECT]] specification.</p>
 
 <h3>Inserting content into an element: the '::before' and '::after'
 pseudo-elements</h3>