Question: List the significant building of the architect who also designed  Kiev?
SPARQL:
SELECT DISTINCT ?uri WHERE { ?x <http://dbpedia.org/ontology/significantBuilding> <http://dbpedia.org/resource/Kiev> . ?x <http://dbpedia.org/ontology/significantBuilding> ?uri  . ?x <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Architect>}