Question: Who wrote the play in which Blanche DuBois is a character?
SPARQL:
SELECT DISTINCT ?uri WHERE { ?x <http://dbpedia.org/property/characters> <http://dbpedia.org/resource/Blanche_DuBois> . ?x <http://dbpedia.org/property/writer> ?uri  . ?x <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Play>}