Question: What were the names of the three ships used by Columbus?
SPARQL query:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> PREFIX onto: <http://dbpedia.org/ontology/> PREFIX dct: <http://purl.org/dc/terms/> PREFIX dbc: <http://dbpedia.org/resource/Category:> select ?uri where { ?uri rdf:type onto:Ship. ?uri dct:subject dbc:Christopher_Columbus. ?uri dct:subject dbc:Exploration_ships. }