diff --git a/documentation/ref-manual/ref-variables.xml b/documentation/ref-manual/ref-variables.xml
index 23be6e312a..7f850ca941 100644
--- a/documentation/ref-manual/ref-variables.xml
+++ b/documentation/ref-manual/ref-variables.xml
@@ -1362,6 +1362,9 @@ Core layer for images cannot be removed
 
       xspace = IMAGE_ROOTFS_EXTRA_SPACE
                     </literallayout>
+                    See the <link linkend='var-IMAGE_OVERHEAD_FACTOR'><filename>IMAGE_OVERHEAD_FACTOR</filename></link>
+                    and <link linkend='var-IMAGE_ROOTFS_EXTRA_SPACE'><filename>IMAGE_ROOTFS_EXTRA_SPACE</filename></link>
+                    variables for related information.
 <!--                    In the above example, <filename>overhead</filename> is defined by the
                     <filename><link linkend='var-IMAGE_OVERHEAD_FACTOR'>IMAGE_OVERHEAD_FACTOR</link></filename>
                     variable, <filename>xspace</filename> is defined by the