diff --git a/dnet-pace-core/src/main/java/eu/dnetlib/pace/clustering/WordsSuffixPrefix.java b/dnet-pace-core/src/main/java/eu/dnetlib/pace/clustering/WordsSuffixPrefix.java
index 80459cbac5..6086ac0a8a 100644
--- a/dnet-pace-core/src/main/java/eu/dnetlib/pace/clustering/WordsSuffixPrefix.java
+++ b/dnet-pace-core/src/main/java/eu/dnetlib/pace/clustering/WordsSuffixPrefix.java
@@ -22,21 +22,6 @@ public class WordsSuffixPrefix extends AbstractClusteringFunction {
     private Collection<String> suffixPrefix(String s, int len, int max) {
 
         final int words = s.split(" ").length;
-
-        // adjust the token length according to the number of words
-        switch (words) {
-            case 1:
-                return Sets.newLinkedHashSet();
-            case 2:
-                return doSuffixPrefix(s, len+2, max, words);
-            case 3:
-                return doSuffixPrefix(s, len+1, max, words);
-            default:
-                return doSuffixPrefix(s, len, max, words);
-        }
-    }
-
-    private Collection<String> doSuffixPrefix(String s, int len, int max, int words) {
         final Set<String> bigrams = Sets.newLinkedHashSet();
         int i = 0;
         while (++i < s.length() && bigrams.size() < max) {
diff --git a/pom.xml.releaseBackup b/pom.xml.releaseBackup
new file mode 100644
index 0000000000..d840af173a
--- /dev/null
+++ b/pom.xml.releaseBackup
@@ -0,0 +1,333 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>eu.dnetlib</groupId>
+    <artifactId>dnet-dedup</artifactId>
+    <version>4.0.2-SNAPSHOT</version>
+
+    <packaging>pom</packaging>
+
+    <url>http://www.d-net.research-infrastructures.eu</url>
+
+    <licenses>
+        <license>
+            <name>The Apache Software License, Version 2.0</name>
+            <url>http://www.apache.org/licenses/LICENSE-2.0.txt</url>
+            <distribution>repo</distribution>
+            <comments>A business-friendly OSS license</comments>
+        </license>
+    </licenses>
+
+    <scm>
+        <developerConnection>scm:git:https://code-repo.d4science.org/D-Net/dnet-dedup.git</developerConnection>
+        <tag>HEAD</tag>
+    </scm>
+
+    <modules>
+        <module>dnet-pace-core</module>
+        <module>dnet-dedup-test</module>
+    </modules>
+
+    <issueManagement>
+        <system>Redmine</system>
+        <url>https://issue.openaire.research-infrastructures.eu/projects/openaire</url>
+    </issueManagement>
+
+
+
+    <distributionManagement>
+        <repository>
+            <id>dnet45-releases</id>
+            <name>D-Net 45 Releases</name>
+            <url>http://maven.research-infrastructures.eu/nexus/content/repositories/dnet45-releases</url>
+            <layout>default</layout>
+        </repository>
+    </distributionManagement>
+
+    <repositories>
+        <repository>
+            <id>dnet-deps</id>
+            <name>dnet-dependencies</name>
+            <url>http://maven.research-infrastructures.eu/nexus/content/repositories/dnet-deps</url>
+            <layout>default</layout>
+        </repository>
+        <repository>
+            <id>dnet45-releases</id>
+            <name>D-Net 45 Releases</name>
+            <url>http://maven.research-infrastructures.eu/nexus/content/repositories/dnet45-releases</url>
+            <layout>default</layout>
+            <snapshots>
+                <enabled>true</enabled>
+            </snapshots>
+        </repository>
+        <repository>
+            <id>dnet45-snapshots</id>
+            <name>D-Net 45 Snapshots</name>
+            <url>http://maven.research-infrastructures.eu/nexus/content/repositories/dnet45-snapshots</url>
+            <layout>default</layout>
+            <snapshots>
+                <enabled>true</enabled>
+            </snapshots>
+        </repository>
+
+        <repository>
+            <id>cloudera</id>
+            <name>Cloudera Repository</name>
+            <url>https://repository.cloudera.com/artifactory/cloudera-repos</url>
+            <releases>
+                <enabled>true</enabled>
+            </releases>
+            <snapshots>
+                <enabled>false</enabled>
+            </snapshots>
+        </repository>
+    </repositories>
+    <build>
+        <directory>target</directory>
+        <outputDirectory>target/classes</outputDirectory>
+        <finalName>${project.artifactId}-${project.version}</finalName>
+        <testOutputDirectory>target/test-classes</testOutputDirectory>
+
+
+
+
+        <!--*************************************************-->
+
+        <pluginManagement>
+            <plugins>
+
+                <plugin>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-compiler-plugin</artifactId>
+                    <version>3.6.0</version>
+                    <configuration>
+                        <source>1.8</source>
+                        <target>1.8</target>
+                        <encoding>${project.build.sourceEncoding}</encoding>
+                    </configuration>
+                </plugin>
+
+                <plugin>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-jar-plugin</artifactId>
+                    <version>3.0.2</version>
+                </plugin>
+
+                <plugin>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-source-plugin</artifactId>
+                    <version>3.0.1</version>
+                    <executions>
+                        <execution>
+                            <id>attach-sources</id>
+                            <phase>verify</phase>
+                            <goals>
+                                <goal>jar-no-fork</goal>
+                            </goals>
+                        </execution>
+                    </executions>
+                </plugin>
+
+                <plugin>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-surefire-plugin</artifactId>
+                    <version>2.19.1</version>
+                    <configuration>
+                        <redirectTestOutputToFile>true</redirectTestOutputToFile>
+                    </configuration>
+                </plugin>
+
+                <plugin>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-javadoc-plugin</artifactId>
+                    <version>2.10.4</version>
+                    <configuration>
+                        <detectLinks>true</detectLinks>
+                    </configuration>
+                </plugin>
+
+                <plugin>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-dependency-plugin</artifactId>
+                    <version>3.0.0</version>
+                </plugin>
+
+                <plugin>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-failsafe-plugin</artifactId>
+                    <version>2.13</version>
+                    <executions>
+                        <execution>
+                            <id>integration-test</id>
+                            <goals>
+                                <goal>integration-test</goal>
+                            </goals>
+                        </execution>
+                        <execution>
+                            <id>verify</id>
+                            <goals>
+                                <goal>verify</goal>
+                            </goals>
+                        </execution>
+                    </executions>
+                </plugin>
+
+            </plugins>
+        </pluginManagement>
+
+        <plugins>
+
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-release-plugin</artifactId>
+                <version>2.5.3</version>
+            </plugin>
+
+        </plugins>
+    </build>
+
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>edu.cmu</groupId>
+                <artifactId>secondstring</artifactId>
+                <version>1.0.0</version>
+            </dependency>
+            <dependency>
+                <groupId>org.antlr</groupId>
+                <artifactId>stringtemplate</artifactId>
+                <version>3.2</version>
+            </dependency>
+
+            <dependency>
+                <groupId>com.fasterxml.jackson.core</groupId>
+                <artifactId>jackson-databind</artifactId>
+                <version>${jackson.version}</version>
+            </dependency>
+
+            <dependency>
+                <groupId>com.fasterxml.jackson.dataformat</groupId>
+                <artifactId>jackson-dataformat-xml</artifactId>
+                <version>${jackson.version}</version>
+            </dependency>
+            <dependency>
+                <groupId>com.fasterxml.jackson.module</groupId>
+                <artifactId>jackson-module-jsonSchema</artifactId>
+                <version>${jackson.version}</version>
+            </dependency>
+
+
+
+            <dependency>
+                <groupId>org.apache.commons</groupId>
+                <artifactId>commons-math3</artifactId>
+                <version>3.6.1</version>
+            </dependency>
+
+            <dependency>
+                <groupId>com.google.guava</groupId>
+                <artifactId>guava</artifactId>
+                <version>${google.guava.version}</version>
+            </dependency>
+            <dependency>
+                <groupId>com.google.code.gson</groupId>
+                <artifactId>gson</artifactId>
+                <version>${google.gson.version}</version>
+            </dependency>
+
+            <dependency>
+                <groupId>org.apache.commons</groupId>
+                <artifactId>commons-lang3</artifactId>
+                <version>${commons.lang.version}</version>
+            </dependency>
+
+            <dependency>
+                <groupId>commons-io</groupId>
+                <artifactId>commons-io</artifactId>
+                <version>${commons.io.version}</version>
+            </dependency>
+            <dependency>
+                <groupId>commons-collections</groupId>
+                <artifactId>commons-collections</artifactId>
+                <version>${commons.collections.version}</version>
+            </dependency>
+            <dependency>
+                <groupId>commons-logging</groupId>
+                <artifactId>commons-logging</artifactId>
+                <version>${commons.logging.version}</version>
+            </dependency>
+            <dependency>
+                <groupId>org.apache.spark</groupId>
+                <artifactId>spark-core_2.11</artifactId>
+                <version>${spark.version}</version>
+                <scope>provided</scope>
+            </dependency>
+            <dependency>
+                <groupId>org.apache.spark</groupId>
+                <artifactId>spark-graphx_2.11</artifactId>
+                <version>${spark.version}</version>
+                <scope>provided</scope>
+            </dependency>
+            <dependency>
+                <groupId>org.apache.spark</groupId>
+                <artifactId>spark-sql_2.11</artifactId>
+                <version>${spark.version}</version>
+                <scope>provided</scope>
+            </dependency>
+            <dependency>
+                <groupId>junit</groupId>
+                <artifactId>junit</artifactId>
+                <version>${junit.version}</version>
+                <scope>test</scope>
+            </dependency>
+            <dependency>
+                <groupId>org.reflections</groupId>
+                <artifactId>reflections</artifactId>
+                <version>0.9.10</version>
+            </dependency>
+
+            <dependency>
+                <groupId>org.scala-lang</groupId>
+                <artifactId>scala-library</artifactId>
+                <version>${scala.version}</version>
+            </dependency>
+
+            <dependency>
+                <groupId>org.apache.oozie</groupId>
+                <artifactId>oozie-client</artifactId>
+                <version>5.1.0</version>
+            </dependency>
+            <dependency>
+                <groupId>com.jayway.jsonpath</groupId>
+                <artifactId>json-path</artifactId>
+                <version>2.4.0</version>
+            </dependency>
+
+
+        </dependencies>
+    </dependencyManagement>
+
+    <properties>
+
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+
+        <google.gson.version>2.2.2</google.gson.version>
+        <google.guava.version>15.0</google.guava.version>
+
+        <spark.version>2.2.0</spark.version>
+        <jackson.version>2.6.6</jackson.version>
+
+        <commons.lang.version>3.5</commons.lang.version>
+        <commons.io.version>2.4</commons.io.version>
+        <commons.collections.version>3.2.1</commons.collections.version>
+        <commons.logging.version>1.1.3</commons.logging.version>
+
+        <junit.version>4.9</junit.version>
+        <scala.version>2.11.8</scala.version>
+
+        <maven.javadoc.failOnError>false</maven.javadoc.failOnError>
+    </properties>
+</project>
diff --git a/release.properties b/release.properties
new file mode 100644
index 0000000000..70a3c40b97
--- /dev/null
+++ b/release.properties
@@ -0,0 +1,22 @@
+#release configuration
+#Thu Jul 02 17:06:39 CEST 2020
+scm.commentPrefix=[maven-release-plugin] 
+pushChanges=true
+project.rel.eu.dnetlib\:dnet-dedup-test=4.0.2
+scm.tag=dnet-dedup-4.0.2
+remoteTagging=true
+project.scm.eu.dnetlib\:dnet-dedup-test.empty=true
+projectVersionPolicyId=default
+scm.url=scm\:git\:https\://code-repo.d4science.org/D-Net/dnet-dedup.git
+scm.tagNameFormat=@{project.artifactId}-@{project.version}
+project.rel.eu.dnetlib\:dnet-dedup=4.0.2
+project.dev.eu.dnetlib\:dnet-pace-core=4.0.3-SNAPSHOT
+preparationGoals=clean verify
+project.scm.eu.dnetlib\:dnet-dedup.tag=HEAD
+project.scm.eu.dnetlib\:dnet-dedup.developerConnection=scm\:git\:https\://code-repo.d4science.org/D-Net/dnet-dedup.git
+exec.snapshotReleasePluginAllowed=false
+project.dev.eu.dnetlib\:dnet-dedup=4.0.3-SNAPSHOT
+project.scm.eu.dnetlib\:dnet-pace-core.empty=true
+project.dev.eu.dnetlib\:dnet-dedup-test=4.0.3-SNAPSHOT
+completedPhase=end-release
+project.rel.eu.dnetlib\:dnet-pace-core=4.0.2