diff --git a/core-java/README.md b/core-java/README.md
index 04b5d92407..1ef4f86e59 100644
--- a/core-java/README.md
+++ b/core-java/README.md
@@ -104,6 +104,7 @@
 - [Guide to DelayQueue](http://www.baeldung.com/java-delay-queue)
 - [Comparing getPath(), getAbsolutePath(), and getCanonicalPath() in Java](http://www.baeldung.com/java-path)
 - [How to Add a Single Element to a Stream](http://www.baeldung.com/java-stream-append-prepend)
+- [Guide to the ConcurrentSkipListMap](http://www.baeldung.com/java-concurrent-skip-list-map)
 - [Difference Between Wait and Sleep in Java](http://www.baeldung.com/java-wait-and-sleep)
 - [LongAdder and LongAccumulator in Java](http://www.baeldung.com/java-longadder-and-longaccumulator)
 - [Using Java MappedByteBuffer](http://www.baeldung.com/java-mapped-byte-buffer)