diff --git a/9999 Personal/Italy Planning.md b/9999 Personal/Italy Planning.md
index 9335dd4c3..ab2a876a9 100644
--- a/9999 Personal/Italy Planning.md	
+++ b/9999 Personal/Italy Planning.md	
@@ -82,5 +82,6 @@ $2,426.91
 | **TOTAL:**    | *$2,404.98* |
 # Itinerary
 
-@chenReachabilityAnalysisCyberPhysical2022
+
+[@chenReachabilityAnalysisNonLinear2015]