Question: What products are made by Tehran based companies?
SPARQL:
SELECT DISTINCT ?uri WHERE { ?x <http://dbpedia.org/property/location> <http://dbpedia.org/resource/Tehran> . ?x <http://dbpedia.org/ontology/product> ?uri  . ?x <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Company>}