Question: Who taught the illustrator of the book " De Divina Proportione"?
Answer(s):
answer: Andrea del Verrocchio
answer: Lorenzo de' Medici
answer: John Argyropoulos

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.illustrator.books_illustrated ns:m.06pqb_7 . 
?c ns:influence.influence_node.influenced_by ?x .
}