Question: Who owns Aldi?
SPARQL query:
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX onto: <http://dbpedia.org/ontology/>
SELECT ?uri ?string
WHERE 
{
	?orga rdf:type onto:Organisation .
	?orga onto:keyPerson ?uri .
	?orga rdfs:label 'Aldi'@en .
	OPTIONAL {?uri rdfs:label ?string . FILTER (lang(?string) = 'en') }
        FILTER (lang(?string) = 'en') 
}