diff --git a/README.md b/README.md
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+++ b/README.md
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 # Research
 The research for the development of advanced rc planes
 
+## Index
+- [🔧 Motor Systems](motor/README.md)
+- [🌀 Fan Blades](fan/README.md)
+
 ## 🛡️ License
 
 This repository is licensed under the [Creative Commons Attribution-NonCommercial 4.0 International License](https://creativecommons.org/licenses/by-nc/4.0/).
diff --git a/fan/README.md b/fan/README.md
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+# 🌀 Fan design and principles