@book{36712,
	author = {Gardner, Martin, and ebrary, Inc.},
	title = {Riddles of the sphinx and other mathematical puzzle tales},
	publisher = {Mathematical Association of America,},
	year = {1987.},
	series = {Anneli Lax New Mathematical Library ;},
	address = {Washington, D.C. :},
	url = {http://site.ebrary.com/lib/rucke/Doc?id=10729374}
}