Question: Name the rivers whose source country's capital is Lusaka?
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:capital <http://dbpedia.org/resource/Lusaka> . ?uri onto:sourceCountry ?x  . ?uri rdf:type onto:River}