Question: Which subsidiary of Lufthansa serves both Dortmund and Berlin Tegel?
SPARQL:
PREFIX res: <http://dbpedia.org/resource/>
PREFIX dbo: <http://dbpedia.org/ontology/> 
SELECT DISTINCT ?uri 
WHERE {
        res:Lufthansa dbo:subsidiary ?uri .
        ?uri dbo:targetAirport res:Dortmund_Airport .
        ?uri dbo:targetAirport res:Berlin_Tegel_Airport .
}