SELECT distinct ?s2 FROM <http://atlas.bio2rdf.org/sparql> WHERE {   ?s1 ?p1 ?o1 .   ?o1 bif:contains "author" .   ?s2 ?p2 ?s1 .   FILTER( regex(?s1, "pubmed") ) } followed by SELECT ?creator, count() FROM <http://localhost:8890/sparql> WHERE {   ?s1 ?p1 .   ?s1 ?p2 ?o2 .   FILTER( regex(?o2, "author"))   ?s1 ?creator . } ORDER BY DESC(count())