Question: In what book did the author who published with Tortilla Flat write about the denizens of the dust bowl?
Answer(s):
answer: The Grapes of Wrath

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:book.author.book_editions_published ns:m.04vbc1j . 
?c ns:book.author.works_written ?x .
?x ns:common.topic.notable_types ns:m.01xryvm .
?x ns:book.written_work.subjects ns:m.0g89m .
}