diff --git a/module2/exo1/toy_document_orgmode_python_en.org b/module2/exo1/toy_document_orgmode_python_en.org
index 046782257b4d8ed4d67f4e1e7b8dd269032061e5..2e12a4bfb5098c216e17f5e23894cf713cf846fc 100644
--- a/module2/exo1/toy_document_orgmode_python_en.org
+++ b/module2/exo1/toy_document_orgmode_python_en.org
@@ -27,7 +27,7 @@ pi
 #+RESULTS:
 
 * 2. *Buffon's needle
-Applying the method of Buffon's needle, we get the *approximation*
+Applying the method of [Buffon's needle[https://en.wikipedia.org/wiki/Buffon%27s_needle_problem]], we get the *approximation*
 #+begin_src python :results output :exports both
 import numpy as np
 np.random.seed(seed=42)