Question: Count all those whose youth club was managed by Luis Enrique.
SPARQL query:
PREFIX res: <http://dbpedia.org/resource/>
PREFIX prop: <http://dbpedia.org/property/>
SELECT DISTINCT COUNT(?uri) WHERE { ?x prop:manager <http://dbpedia.org/resource/Luis_Enrique_(footballer)> . ?uri prop:youthclubs ?x . }