Question: What was the last Superbowl won by the team whose fight song is "Steelers Polka"?
Answer(s):
answer: Super Bowl XLIII

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ?c)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
?c ns:sports.sports_team.fight_song ns:m.0j_8yp9 . 
?c ns:sports.sports_team.championships ?x .
?x ns:common.topic.notable_types ns:m.01xljv1 .
?x ns:time.event.end_date ?sk0 .
}
ORDER BY DESC(xsd:datetime(?sk0))
LIMIT 1