diff --git a/README.md b/README.md
index d1b707c..cbe5a94 100644
--- a/README.md
+++ b/README.md
@@ -21,3 +21,7 @@ Chaque seconde passé dans le jeu rapporte 1 point.
     [`js/lib`](./js/lib/).
 
 -   Placer une image `player.png` dans le dossier [`assets/images`](./assets/images/).
+
+## Sources
+
+-   [Collision example](https://github.com/stemkoski/stemkoski.github.com/blob/master/Three.js/Collision-Detection.html)