diff --git a/00.brainstorming-pedagogical-teams/40.collection-existing-pedagogical-content/04.reference-frames-coordinate-systems/textbook.fr.md b/00.brainstorming-pedagogical-teams/40.collection-existing-pedagogical-content/04.reference-frames-coordinate-systems/textbook.fr.md
index 61dda240a..14a33df64 100644
--- a/00.brainstorming-pedagogical-teams/40.collection-existing-pedagogical-content/04.reference-frames-coordinate-systems/textbook.fr.md
+++ b/00.brainstorming-pedagogical-teams/40.collection-existing-pedagogical-content/04.reference-frames-coordinate-systems/textbook.fr.md
@@ -618,7 +618,7 @@ base ortogonal dependiente de la posición de $`M`$ / base orthogonale dépendan
 de la position de $`M`$ / orthogonal basis dependent of the position of $`M`$.
 
 * **N3 ($`\rightarrow`$ N4)**<br>
-[ES] La norma del vector $`\partial\overrightarrow{OM}_{\rho}}=\overrightarrow{dl_{\rho}}`$ 
+[ES] La norma del vector $`\partial\overrightarrow{OM}_{\rho}=\overrightarrow{dl_{\rho}}`$ 
 es el elemento escalar de linea $`dl_{\rho}`$, entonces el vector $`\overrightarrow{e_{\rho}}`$ 
 se escribe :<br>
 [FR] La norme du vecteur $`\partial\overrightarrow{OM}_{\rho}=\overrightarrow{dl_{\rho}}`$