Question: Give me all soccer clubs in Spain.
SPARQL query:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX onto: <http://dbpedia.org/ontology/>
PREFIX prop: <http://dbpedia.org/property/>
SELECT DISTINCT ?uri ?string
WHERE 
{
	?uri rdf:type onto:SoccerClub .
        { ?uri onto:ground ?ground . }
        UNION 
        { ?uri prop:ground ?ground . }
        FILTER (regex(?ground, 'Spain')) .
        OPTIONAL {?uri rdfs:label ?string. FILTER (lang(?string) = 'en') }
}