@book{104395,
	author = {Tokheim, Roger L.},
	title = {Schaum's outline of theory and problems of digital principles /},
	publisher = {McGraw-Hill,},
	year = {c1994.},
	address = {New York :},
	edition = {3rd ed.},
	note = {Includes index.},
	url = {http://www.loc.gov/catdir/toc/mh031/93000064.html}
}