diff --git a/articles/Gamma correction - Wikipedia/Gamma correction - Wikipedia.xopp.xml b/articles/Gamma correction - Wikipedia/Gamma correction - Wikipedia.xopp.xml
index 99d0939..6fa781a 100644
--- a/articles/Gamma correction - Wikipedia/Gamma correction - Wikipedia.xopp.xml	
+++ b/articles/Gamma correction - Wikipedia/Gamma correction - Wikipedia.xopp.xml	
@@ -29,7 +29,9 @@
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+    <layer>
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+    </layer>
   </page>
   <page width="596.00000000" height="842.00000000">
     <background type="pdf" pageno="3"/>