Question: What theory areas were studied by the author of The Correspondence of Charles Darwin, Volume 12?
Answer(s):
answer: Naturalist
answer: Geologist
answer: Scientist
answer: Biologist
answer: Writer

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.04vrrwl . 
?c ns:people.person.profession ?x .
}