SELECT ?mbox1, ?mbox2, ?uri
WHERE
	(foaf::depiction ?x ?img)
	(foaf::depiction ?z ?img)
	(foaf::thumbnail ?img ?uri)
	(foaf::mbox ?x ?mbox1)
	(foaf::mbox ?z ?mbox2)
USING foaf for http://xmlns.com/foaf/0.1/