Question: Greek writers have won which award?
SPARQL:
SELECT DISTINCT ?uri WHERE { ?x <http://dbpedia.org/property/ethnicity> <http://dbpedia.org/resource/Greeks> . ?x <http://dbpedia.org/ontology/award> ?uri  . ?x <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Writer>}