@book{10497,
	author = {Grimaldi, Ralph.},
	title = {Discrete and combinatorial mathematics :},
	publisher = {Addison Wesley Publishing Company,},
	year = {2005.},
	address = {[S.l.] :},
	edition = {4th ed.},
	url = {http://www.amazon.com/exec/obidos/ASIN/B004HP1E5Y/chopaconline-20}
}