diff --git a/src/main/java/org/gcube/data/publishing/ckan2zenodo/Translator.java b/src/main/java/org/gcube/data/publishing/ckan2zenodo/Translator.java
index 45e583a..53c09f5 100644
--- a/src/main/java/org/gcube/data/publishing/ckan2zenodo/Translator.java
+++ b/src/main/java/org/gcube/data/publishing/ckan2zenodo/Translator.java
@@ -3,6 +3,7 @@ package org.gcube.data.publishing.ckan2zenodo;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.regex.Matcher;
@@ -209,7 +210,7 @@ public class Translator {
 		try {
 		ObjectMapper mapper=Parsing.getMapper();
 		DocumentContext sourceCtx=JsonPath.using(Parsing.JSON_PATH_ALWAYS_LIST_CONFIG).parse(source.getContent());
-		ArrayList<CkanResource> toReturn=new ArrayList<>();
+		HashSet<CkanResource> toReturn=new HashSet();
 		for(Filter f:resourceFilter.getFilters()) {			
 			JSONArray filtered=sourceCtx.read(f.getConditions().get(0));
 			for(Object obj:filtered) {
@@ -219,7 +220,7 @@ public class Translator {
 			}
 		}	
 		
-		return toReturn;
+		return new ArrayList<CkanResource>(toReturn);
 		}catch(Throwable t) {
 			log.error("Unable to filter resources. ",t);
 			throw new TransformationException("Unable to filter "+source.getName()+" resources",t);
diff --git a/src/main/java/org/gcube/data/publishing/ckan2zenodo/model/CkanResource.java b/src/main/java/org/gcube/data/publishing/ckan2zenodo/model/CkanResource.java
index f5d00fd..d8a96d4 100644
--- a/src/main/java/org/gcube/data/publishing/ckan2zenodo/model/CkanResource.java
+++ b/src/main/java/org/gcube/data/publishing/ckan2zenodo/model/CkanResource.java
@@ -29,4 +29,35 @@ public class CkanResource{
 	private String id;
 	private String resource_type;
 	private String size;
+	@Override
+	public int hashCode() {
+		final int prime = 31;
+		int result = 1;
+		result = prime * result + ((name == null) ? 0 : name.hashCode());
+		result = prime * result + ((url == null) ? 0 : url.hashCode());
+		return result;
+	}
+	@Override
+	public boolean equals(Object obj) {
+		if (this == obj)
+			return true;
+		if (obj == null)
+			return false;
+		if (getClass() != obj.getClass())
+			return false;
+		CkanResource other = (CkanResource) obj;
+		if (name == null) {
+			if (other.name != null)
+				return false;
+		} else if (!name.equals(other.name))
+			return false;
+		if (url == null) {
+			if (other.url != null)
+				return false;
+		} else if (!url.equals(other.url))
+			return false;
+		return true;
+	}
+	
+	
 }