Question: Which railway line goes through the stations which are a part of the North Caucasus railway?
SPARQL:
SELECT DISTINCT ?uri WHERE { ?x <http://dbpedia.org/ontology/type> <http://dbpedia.org/resource/North_Caucasus_Railway> . ?x <http://dbpedia.org/ontology/servingRailwayLine> ?uri  . ?x <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Station>}