Question: Name the river whose source region is North-Western Province, Zambia and source location is Ikelenge  District?
SPARQL query:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX prop: <http://dbpedia.org/property/>
PREFIX onto: <http://dbpedia.org/ontology/>
SELECT DISTINCT ?uri WHERE {?uri prop:sourceRegion <http://dbpedia.org/resource/North-Western_Province,_Zambia> . ?uri prop:sourceLocation <http://dbpedia.org/resource/Ikelenge_District>  . ?uri rdf:type onto:River}