Question: What cities does the river goes through, whose tributary is the little black river in Arkansas?
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:leftTributary <http://dbpedia.org/resource/Little_Black_River_(Missouri_-_Arkansas)> . ?x onto:city ?uri  . ?x rdf:type onto:River}