diff --git a/content/posts/extremal-graph-theory.md b/content/posts/extremal-graph-theory.md
index c7d4850..93a746d 100644
--- a/content/posts/extremal-graph-theory.md
+++ b/content/posts/extremal-graph-theory.md
@@ -41,5 +41,5 @@ Alek wrote up the same [proof of this theorem on his blog](https://awestover.git
 
 ## Further reading
 
-- https://www.mit.edu/~shint/handouts/ExtremalGraphTheory.pdf
+- https://www.mit.edu/~shint/handouts/ExtremalGraphTheory.pdf (contains another proof of that theorem)
 - https://ocw.mit.edu/courses/18-217-graph-theory-and-additive-combinatorics-fall-2019/