Question: What are some non fiction subjects dealt with in fantasy novels?
SPARQL:
SELECT DISTINCT ?uri WHERE { ?x <http://dbpedia.org/ontology/literaryGenre> <http://dbpedia.org/resource/Fantasy> . ?x <http://dbpedia.org/ontology/nonFictionSubject> ?uri  . ?x <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Book>}