diff --git a/BurnOutSharp/ProtectionType/CrypKey.cs b/BurnOutSharp/ProtectionType/CrypKey.cs
index ece73b57..21ce02fa 100644
--- a/BurnOutSharp/ProtectionType/CrypKey.cs
+++ b/BurnOutSharp/ProtectionType/CrypKey.cs
@@ -6,5 +6,6 @@
 
         // https://github.com/horsicq/Detect-It-Easy/blob/master/db/PE/CrypKey%20Installer.1.sg
         // https://github.com/horsicq/Detect-It-Easy/blob/master/db/PE/CrypKey.2.sg
+        // https://github.com/wolfram77web/app-peid/blob/master/userdb.txt
     }
 }