Question: What are the things whose leader was a monarch Willem-Alexander of the Netherlands?
SPARQL query:
PREFIX res: <http://dbpedia.org/resource/>
PREFIX onto: <http://dbpedia.org/ontology/>
SELECT DISTINCT ?uri WHERE { ?x onto:monarch <http://dbpedia.org/resource/Willem-Alexander_of_the_Netherlands> . ?uri onto:leader ?x . }