diff --git a/sources/teaching/economic-calculus/index.org b/sources/teaching/economic-calculus/index.org
index af7b719..2932b5a 100644
--- a/sources/teaching/economic-calculus/index.org
+++ b/sources/teaching/economic-calculus/index.org
@@ -35,7 +35,7 @@
     + Éléments de correction pour l'exercice 12 [[https://le-mans.adjemian.eu/calcul-%C3%A9conomique/td/1/Exo-12-td-1.pdf][{pdf}]]
   - Fiche de TD n°2 [[https://le-mans.adjemian.eu/calcul-%C3%A9conomique/td/2/td.pdf][{pdf}]]
   - Fiche de TD n°3 [[https://le-mans.adjemian.eu/calcul-%C3%A9conomique/td/3/td.pdf][{pdf}]]
-  - Fiche de TD n°4 {pdf}
+  - Fiche de TD n°4 [[https://le-mans.adjemian.eu/calcul-%C3%A9conomique/td/4/td.pdf][{pdf}]]
 * Tableaux (TD)
   - Lundi 2 novembre 2020, 16h00-18h00 [[https://le-mans.adjemian.eu/calcul-%C3%A9conomique/gribouille/td-calcul-eco-1.pdf][{pdf}]].
 * Sujets d'examen