diff --git a/README.md b/README.md
index a986a6c..b19e8ab 100644
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+++ b/README.md
@@ -166,7 +166,7 @@ Courses | Duration | Effort | Prerequisites
 
 #### Readings
 - **Required** to learn about monads, laziness, purity: [Learn You a Haskell for a Great Good!](http://learnyouahaskell.com/)
-  - **OBS**: probably the best resource to learn Haskell: [Haskell Programming from First Principles](http://haskellbook.com/) `paid`
+  - **Note**: probably the best resource to learn Haskell: [Haskell Programming from First Principles](http://haskellbook.com/) `paid`
 - **Required**, to learn about logic programming, backtracking, unification: [Learn Prolog Now!](http://www.learnprolognow.org/)
 
 ### Core math