@book{73727,
	author = {Freudenthal, Hans, and ebrary, Inc.},
	title = {Revisiting mathematics education},
	publisher = {Kluwer Academic Publishers,},
	year = {c1991.},
	series = {Mathematics education library ;},
	address = {Dordrecht ;},
	url = {http://site.ebrary.com/lib/rucke/Doc?id=10047446}
}