Question: list  the producer of the movies in which Rosemarie DeWitt in the star cast?
SPARQL:
SELECT DISTINCT ?uri WHERE { ?x <http://dbpedia.org/property/starring> <http://dbpedia.org/resource/Rosemarie_DeWitt> . ?x <http://dbpedia.org/property/producer> ?uri  . ?x <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Film>}