diff --git a/core-java-modules/core-java-collections-4/README.md b/core-java-modules/core-java-collections-4/README.md
index 7a97ebd863..9d3ee5e657 100644
--- a/core-java-modules/core-java-collections-4/README.md
+++ b/core-java-modules/core-java-collections-4/README.md
@@ -13,3 +13,4 @@
 - [Difference Between Java Enumeration and Iterator](https://www.baeldung.com/java-enumeration-vs-iterator)
 - [Sort Collection of Objects by Multiple Fields in Java](https://www.baeldung.com/java-sort-collection-multiple-fields)
 - [Guide to Java PriorityQueue](https://www.baeldung.com/java-priorityqueue)
+- [Java Generics PECS – Producer Extends Consumer Super](https://www.baeldung.com/java-generics-pecs)