@book{6728,
	author = {Tocci, Ronald J. and Widmer, Neal S.},
	title = {Digital systems: principles and applications. /},
	publisher = {Prentice Hall,},
	year = {1995.},
	address = {Englewood Cliffs :},
	edition = {6th ed.},
	note = {Includes appendix and index.}
}