diff --git a/source/part-1-workspace/maintainable-applications/maintainable-applications.adoc b/source/part-1-workspace/maintainable-applications/maintainable-applications.adoc
index f0a3b2e..baaee91 100644
--- a/source/part-1-workspace/maintainable-applications/maintainable-applications.adoc
+++ b/source/part-1-workspace/maintainable-applications/maintainable-applications.adoc
@@ -1,5 +1,11 @@
 === Bonnes pratiques
 
+[quote]
+----
+The primary cost of maintenance is in spelunking and risk
+-- Robert C. Martin, Clean Architecture, page 139
+----
+
 Pour cette section, nous nous basons sur un résumé de l'ebook **Building Maintenable Software** disponible chez http://shop.oreilly.com/product/0636920049555.do[O'Reilly].
 
 Ce livre répartit un ensemble de conseils parmi quatre niveaux de composants: