Question: How many causes of death have been associated with American citizens?
SPARQL query:
PREFIX res: <http://dbpedia.org/resource/>
PREFIX prop: <http://dbpedia.org/property/>
PREFIX onto: <http://dbpedia.org/ontology/>
SELECT DISTINCT COUNT(?uri) WHERE { ?x prop:citizenship <http://dbpedia.org/resource/United_States> . ?x onto:deathCause ?uri . }