Question: Name all the soccer players who played in a under 18 club for La Liga?
SPARQL query:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX prop: <http://dbpedia.org/property/>
PREFIX onto: <http://dbpedia.org/ontology/>
SELECT DISTINCT ?uri WHERE { ?x prop:league <http://dbpedia.org/resource/La_Liga> . ?uri prop:youthclubs ?x  . ?uri rdf:type onto:SoccerPlayer}