Question: Do you know who influenced the writer of Langston in Harlem?
Answer(s):
answer: Walt Whitman

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:theater.theatrical_lyricist.play_lyrics_written ns:m.0wr00wj . 
?c ns:influence.influence_node.influenced_by ?x .
}