@book{170423,
	author = {Glasersfeld, Ernst von. and ebrary, Inc.},
	title = {Radical constructivism in mathematics education},
	publisher = {Kluwer Academic,},
	year = {c2002.},
	series = {Mathematics education library ;},
	address = {New York :},
	url = {http://site.ebrary.com/lib/rucke/Doc?id=10051626}
}