diff --git a/00.brainstorming-pedagogical-teams/40.collection-existing-pedagogical-content/42.relativistic-mechanics/30.n3/20.overview/cheatsheet.fr.md b/00.brainstorming-pedagogical-teams/40.collection-existing-pedagogical-content/42.relativistic-mechanics/30.n3/20.overview/cheatsheet.fr.md
index 48cbd8263..7afd18115 100644
--- a/00.brainstorming-pedagogical-teams/40.collection-existing-pedagogical-content/42.relativistic-mechanics/30.n3/20.overview/cheatsheet.fr.md
+++ b/00.brainstorming-pedagogical-teams/40.collection-existing-pedagogical-content/42.relativistic-mechanics/30.n3/20.overview/cheatsheet.fr.md
@@ -6,6 +6,8 @@ visible: false
 lessons:
     - slug: modern-versus-classical-physics-3
       order: 1
+    - slug: relativity-linear-3
+      order: 2
 ---
 
 #### Mécaniques relativistes, n3, synthèse