diff --git a/2025/Secure erase under macOS.md b/2025/Secure erase under macOS.md
index bd16095..555d83c 100644
--- a/2025/Secure erase under macOS.md	
+++ b/2025/Secure erase under macOS.md	
@@ -22,4 +22,7 @@ From this [post at Backblaze](https://www.backblaze.com/blog/how-to-wipe-a-mac-
 
 > Something to remember is that the more extensive the erase procedure, the longer it will take.
 
-Sourcehttps://apple.stackexchange.com/a/405605
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+Source: <https://apple.stackexchange.com/a/405605>
+
+Extra for reinstall clean old version:
+https://www.macworld.com/article/671911/how-to-get-old-macos-download-big-sur-catalina-mojave-and-more.html
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