diff --git a/tools for thinking.md b/tools for thinking.md
index b3e19669c..6f260f37c 100644
--- a/tools for thinking.md	
+++ b/tools for thinking.md	
@@ -293,6 +293,7 @@
   - Putting all nodes side by side in a single tool (interface) is instrumental.
   - thebrain's flexibility is one of the most attractive factors.
   - [[howard rheingold]] it externalizes your memory
+    - [[the magic number 7]]
 
   
 ## [[Q&A]]