What is the sea connected to Oulu and Turku?
SELECT DISTINCT ?uri WHERE { ?uri <http://dbpedia.org/property/cities> <http://dbpedia.org/resource/Oulu> . ?uri <http://dbpedia.org/property/cities> <http://dbpedia.org/resource/Turku> . ?uri <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Sea>}
Oulu Turku