Question: What is the sea whose cities are Gdask and Oulu?
SPARQL query:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX prop: <http://dbpedia.org/property/>
PREFIX onto: <http://dbpedia.org/ontology/>
SELECT DISTINCT ?uri WHERE { ?uri prop:cities <http://dbpedia.org/resource/Gdańsk> . ?uri prop:cities <http://dbpedia.org/resource/Oulu> . ?uri rdf:type onto:Sea}