Question: Which companies work in the aerospace industry as well as on nuclear reactor technology?
SPARQL:
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/>
PREFIX res:  <http://dbpedia.org/resource/>
PREFIX prop: <http://dbpedia.org/property/>
SELECT ?uri ?string
WHERE
{ 
	?uri  rdf:type onto:Company  .
	?uri prop:industry res:Aerospace .
        ?uri prop:industry res:Nuclear_reactor_technology .
	OPTIONAL {?uri rdfs:label ?string . FILTER (lang(?string) = 'en') }
}