Display information on interaction of entities and their information in the bibliography from Irefindex and Pubmed databases (Federated query)

Endpoints: 
Query: 
select ?label ?Pubmed ?label_article ?author_name ?last_name where{ {SERVICE <$endpoint-1$> { ?s<http://www.w3.org/2000/01/rdf-schema#label>?label . ?s<http://bio2rdf.org/irefindex_vocabulary:article>?Pubmed . FILTER regex (?label, "??label") } } {SERVICE <$endpoint-2$> { OPTIONAL{ ?Pubmed<http://www.w3.org/2000/01/rdf-schema#label>?label_article . } OPTIONAL{ ?Pubmed<http://bio2rdf.org/pubmed_vocabulary:author>?author_article . } OPTIONAL{ ?author_article<http://bio2rdf.org/pubmed_vocabulary:fore_name>?author_name . } OPTIONAL{ ?author_article<http://bio2rdf.org/pubmed_vocabulary:last_name>?last_name . } } } } limit ??number
Statement: 

Display information on interaction of entities and their information in the bibliography from Irefindex and Pubmed databases $label$ (e.g. P33338 ) A limit of results per page $number$ (e.g. 10)