[css-images] Use a consistent biblio term.

Author: tabatkins

css-images/Overview.bs

@@ -84,7 +84,7 @@ Image References and Image Slices: the <<url>> type and ''url()'' notation {#url
 ------------------------------------------------------------------------------------------
 
 	The simplest way to indicate an image is to reference an image file by URL.
-	This can be done with the ''url()'' notation, defined in [[css3val]].
+	This can be done with the ''url()'' notation, defined in [[css-values-3]].
 
 	<div class="example">
 		In the example below, a background image is specified with ''url()''syntax:
@@ -126,7 +126,7 @@ Image Fallbacks and Annotations: the ''image()'' notation {#image-notation}
 	A <<string>> used in ''image()'' represents a <<url>>.
 	As usual for URLs in CSS,
 	relative URLs are resolved to an absolute URL
-	(as described in Values &amp; Units [[!CSS3VAL]])
+	(as described in Values &amp; Units [[!css-values-3]])
 	when a specified ''image()'' value is computed.
 
 	If the image has an orientation specified in its metadata,
@@ -684,7 +684,7 @@ Radial Gradients: the ''radial-gradient()'' notation {#radial-gradients}
 			Determines the <dfn dfn>gradient center</dfn> of the gradient.
 			The <<position>> value type
 			(which is also used for 'background-position')
-			is defined in [[!CSS3VAL]],
+			is defined in [[!css-values-3]],
 			and is resolved using the center-point as the object area
 			and the <a>gradient box</a> as the positioning area.
 			If this argument is omitted,
@@ -1567,7 +1567,7 @@ Positioning Objects: the 'object-position' property {#the-object-position}
 	The 'object-position' property determines the alignment of the replaced element inside its box.
 	The <<position>> value type
 	(which is also used for 'background-position')
-	is defined in [[!CSS3VAL]],
+	is defined in [[!css-values-3]],
 	and is resolved using the <a>concrete object size</a> as the object area
 	and the content box as the positioning area.