diff --git a/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/SparkGenerateDoiBoost.scala b/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/SparkGenerateDoiBoost.scala
index 11f9828db4..f5672b7f46 100644
--- a/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/SparkGenerateDoiBoost.scala
+++ b/dhp-workflows/dhp-doiboost/src/main/java/eu/dnetlib/doiboost/SparkGenerateDoiBoost.scala
@@ -7,6 +7,7 @@ import eu.dnetlib.dhp.schema.oaf.{Organization, Publication, Relation, Dataset =
 import eu.dnetlib.doiboost.mag.ConversionUtil
 import org.apache.commons.io.IOUtils
 import org.apache.spark.SparkConf
+import org.apache.spark.sql.expressions.Aggregator
 import org.apache.spark.sql.functions.col
 import org.apache.spark.sql.{Dataset, Encoder, Encoders, SaveMode, SparkSession}
 import org.slf4j.{Logger, LoggerFactory}
@@ -15,6 +16,9 @@ import scala.collection.JavaConverters._
 
 object SparkGenerateDoiBoost {
 
+
+
+
   def main(args: Array[String]): Unit = {
 
     val logger: Logger = LoggerFactory.getLogger(getClass)
@@ -33,6 +37,54 @@ object SparkGenerateDoiBoost {
     val hostedByMapPath = parser.get("hostedByMapPath")
     val workingDirPath = parser.get("workingPath")
 
+    val crossrefAggregator = new Aggregator[(String, Publication), Publication, Publication] with Serializable {
+      override def zero: Publication = new Publication
+
+      override def reduce(b: Publication, a: (String, Publication)): Publication = {
+
+        if (b == null) {
+          if (a != null && a._2 != null) {
+            a._2.setId(a._1)
+            return a._2
+          }
+        }
+        else {
+          if (a != null && a._2 != null) {
+            b.mergeFrom(a._2)
+            b.setId(a._1)
+            val authors =AuthorMerger.mergeAuthor(b.getAuthor, a._2.getAuthor)
+            b.setAuthor(authors)
+            return b
+          }
+        }
+        new Publication
+      }
+
+      override def merge(b1: Publication, b2: Publication): Publication = {
+        if (b1 == null) {
+          if (b2 != null)
+            return b2
+        }
+        else {
+          if (b2 != null ) {
+            b1.mergeFrom(b2)
+            val authors =AuthorMerger.mergeAuthor(b1.getAuthor, b2.getAuthor)
+            b1.setAuthor(authors)
+            if (b2.getId!= null && b2.getId.nonEmpty)
+              b1.setId(b2.getId)
+            return b1
+          }
+        }
+        new Publication
+      }
+
+      override def finish(reduction: Publication): Publication = reduction
+
+      override def bufferEncoder: Encoder[Publication] = Encoders.kryo[Publication]
+
+      override def outputEncoder: Encoder[Publication] = Encoders.kryo[Publication]
+    }
+
 
     implicit val mapEncoderPub: Encoder[Publication] = Encoders.kryo[Publication]
     implicit val mapEncoderOrg: Encoder[Organization] = Encoders.kryo[Organization]
@@ -77,6 +129,10 @@ object SparkGenerateDoiBoost {
 
     doiBoostPublication.joinWith(hostedByDataset, doiBoostPublication("_1").equalTo(hostedByDataset("_1")), "left")
       .map(DoiBoostMappingUtil.fixPublication)
+      .map(p => (p.getId, p))
+      .groupByKey(_._1)
+      .agg(crossrefAggregator.toColumn)
+      .map(p => p._2)
       .write.mode(SaveMode.Overwrite).save(s"$workingDirPath/doiBoostPublicationFiltered")
 
     val affiliationPath = parser.get("affiliationPath")