diff --git a/java-collections-maps/README.md b/java-collections-maps/README.md
index 4883e0e1b6..ca7fee1d21 100644
--- a/java-collections-maps/README.md
+++ b/java-collections-maps/README.md
@@ -14,4 +14,5 @@
 - [Initialize a HashMap in Java](https://www.baeldung.com/java-initialize-hashmap)
 - [Get the Key for a Value from a Java Map](https://www.baeldung.com/java-map-key-from-value)
 - [Sort a HashMap in Java](https://www.baeldung.com/java-hashmap-sort)
-- [Finding the Highest Value in a Java Map](https://www.baeldung.com/java-find-map-max)
\ No newline at end of file
+- [Finding the Highest Value in a Java Map](https://www.baeldung.com/java-find-map-max)
+- [Merging Two Maps with Java 8](https://www.baeldung.com/java-merge-maps)
diff --git a/core-java/src/test/java/com/baeldung/guava/GuavaBiMapUnitTest.java b/java-collections-maps/src/test/java/com/baeldung/guava/GuavaBiMapUnitTest.java
similarity index 100%
rename from core-java/src/test/java/com/baeldung/guava/GuavaBiMapUnitTest.java
rename to java-collections-maps/src/test/java/com/baeldung/guava/GuavaBiMapUnitTest.java
diff --git a/parent-spring-4/pom.xml b/parent-spring-4/pom.xml
index d1b1298013..9b3c42599b 100644
--- a/parent-spring-4/pom.xml
+++ b/parent-spring-4/pom.xml
@@ -29,7 +29,7 @@
     </dependencies>
 
     <properties>
-        <spring.version>4.3.17.RELEASE</spring.version>
+        <spring.version>4.3.20.RELEASE</spring.version>
         <junit.jupiter.version>5.0.2</junit.jupiter.version>
     </properties>