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