@book{7425,
	author = {Lipschutz, Seymour. and Lipson, Marc.},
	title = {Schaum's outline of theory and problems of discrete mathematics },
	publisher = {McGraw-Hill,},
	year = {c1997.},
	series = {Schaum's outline series},
	address = {New York :},
	edition = {2nd ed.},
	note = {Includes index.}
}