Question: Who was the author who published editions for Frankenstein, (Oxford Playscripts) both parents names?
Answer(s):
answer: William Godwin
answer: Mary Wollstonecraft

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.04t_1sf . 
?c ns:people.person.parents ?x .
}