@book{889,
	author = {Hummel, Kenneth E.},
	title = {Introductory concepts for abstract mathematics /},
	publisher = {Chapman & Hall,},
	year = {c2000.},
	address = {Boca Raton, Fla. :},
	note = {Includes index.},
	url = {http://www.loc.gov/catdir/enhancements/fy0646/00021301-d.html}
}