Question: Which planet was discovered by Johann Gottfired and Urbain Le Verrier ?
SPARQL:
SELECT DISTINCT ?uri WHERE {?uri <http://dbpedia.org/property/discoverer> <http://dbpedia.org/resource/Johann_Gottfried_Galle> . ?uri <http://dbpedia.org/ontology/discoverer> <http://dbpedia.org/resource/Urbain_Le_Verrier>  . ?uri <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Planet>}