@book{31721,
	author = {Tokheim, Roger L.},
	title = {Digital electronics /},
	publisher = {Glencoe,},
	year = {c1994.},
	series = {Basic skills in electricity and electronics},
	address = {New York :},
	edition = {4th ed.},
	note = {Includes index.},
	url = {http://www.loc.gov/catdir/description/mh051/93002132.html}
}