What is the {periodical literature} for {mouthpiece} of {Southwest Airlines}
What is the name of the Southwest Airlines company magazine?
 select distinct ?obj where { wd:Q503308 wdt:P2813 ?obj . ?obj wdt:P31 wd:Q1002697 } 
select distinct ?obj where { ?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q503308> . ?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P2813> . ?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/Q1002697> } 
What is the title of the Southwest Carriers company magazine?