diff --git a/core-java-modules/core-java-collections-maps-4/README.md b/core-java-modules/core-java-collections-maps-4/README.md
index 54ab60da7d..cb25aa5a8a 100644
--- a/core-java-modules/core-java-collections-maps-4/README.md
+++ b/core-java-modules/core-java-collections-maps-4/README.md
@@ -4,3 +4,4 @@ This module contains articles about Map data structures in Java.
 
 ### Relevant Articles: 
 - [Using a Custom Class as a Key in a Java HashMap](https://www.baeldung.com/java-custom-class-map-key)
+- [Nested HashMaps Examples in Java](https://www.baeldung.com/java-nested-hashmaps)