Question: The ISBN 9780140447521 refers to which Niccolo Machiavelli book?
Answer(s):
answer: The Prince

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ns:m.05cvs)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
ns:m.05cvs ns:book.author.book_editions_published ?x .
?x ns:book.book_edition.isbn ns:m.077894y . 
}