Related content from Europeana is shown under the PIONIER Network Digital Libraries Federation search results. As they are a Europeana aggregator, their own objects in Europeana are filtered out of the API responses in order to avoid duplicate hits.

For more information about the implementation read the case study: http://pro.europeana.eu/c/document_library/get_file?uuid=2d0dffca-ce70-4493-83b3-f9ff890cda21&groupId=462475