Question: Which cities have the river one of whose Tributary is the Missouri's big spring?
SPARQL query:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX onto: <http://dbpedia.org/ontology/>
SELECT DISTINCT ?uri WHERE { ?x onto:rightTributary <http://dbpedia.org/resource/Big_Spring_(Missouri)> . ?x onto:city ?uri  . ?x rdf:type onto:River}