SELECT ?document (COUNT(?document) as ?count)
WHERE {
	GRAPH prj:disease_gene_microbe_small {
		?denotation tao:denoted_by ?span ; a __AN_ENTITY__ .
      #e.g. __AN_ENTITY__ : http://disease-ontology.org/term/DOID:0060192
	}
    #?span tao:belongs_to ?document . #NOT WORKING, somehow the project is not being RDF-ized properly
}
GROUP BY ?document
ORDER BY DESC(?count)