What is the {international airport} for {airline hub} of {Delta Air Lines}
What worldwide air terminal is Delta Discuss Lines' hub?
What international airport is Delta Air Lines' hub?
SELECT DISTINCT ?j WHERE { ?j rdf:type ontology:international_airport . resource:Delta_Air_Lines property:airline_hub ?j }
select distinct ?obj where { ?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q188920> . ?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P113> . ?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj . ?obj <http://www.wikidata.org/entity/P31> <http://wikidata.dbpedia.org/resource/Q644371> } 
 select distinct ?obj where { wd:Q188920 wdt:P113 ?obj . ?obj wdt:P31 wd:Q644371 } 
Cincinnati/Northern Kentucky International Airport Hartsfield–Jackson Atlanta International Airport LaGuardia Airport Salt Lake City International Airport Detroit Metropolitan Wayne County Airport Logan International Airport Memphis International Airport Minneapolis–Saint Paul International Airport John F. Kennedy International Airport Los Angeles International Airport Amsterdam Airport Schiphol Seattle–Tacoma International Airport Narita International Airport Paris-Charles de Gaulle Airport