SELECT DISTINCT ?uri WHERE { <http://dbpedia.org/resource/Callisto_(moon)> <http://dbpedia.org/ontology/discoverer> ?uri }
Who discovered Callisto ?
SELECT DISTINCT ?f WHERE { resource:Callisto_(moon) property:discoverer ?f }
Galileo Galilei
[Galileo Galilei] is the discoverer of Callisto.
[Galileo Galicia] is Callisto's discoverer.
[Galileo Galilei] is the person who discovered Callisto.
[Galileo Galileo] is the explorer of Callisto.