Question: Who are the parent of the person quoted for saying "Oh, that peace may come."?
Answer(s):
answer: Prince Edward, Duke of Kent and Strathearn
answer: Princess Victoria of Saxe-Coburg-Saalfeld

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:people.person.quotations ns:m.0g_mjcx . 
?c ns:people.person.parents ?x .
}