[mediaqueries] More cross referencing for easier readability

Author: frivoal

mediaqueries/Overview.bs

@@ -917,6 +917,8 @@ width</h3>
 	For paged media, this is the width of the page box
 	(as described by CSS2, section 13.2 [[!CSS21]]).
 
+	<<length>>s are interpreted according to [[#units]].
+
 	Negative <<length>>s are invalid.
 
 	<div class="example">
@@ -956,8 +958,9 @@ height</h3>
 	For continuous media, this is the height of the viewport including the size of a rendered scroll bar (if any).
 	For paged media, this is the height of the page box.
 
-	Negative <<length>>s are invalid.
+	<<length>>s are interpreted according to [[#units]].
 
+	Negative <<length>>s are invalid.
 
 <h3 id='aspect-ratio'>
 aspect-ratio</h3>