@book{589,
	author = {Tocci, Ronald J. and Urbina Medal, Edmundo Gerardo,},
	title = {Sistemas Digitales: Principios y Aplicaciones /},
	publisher = {Prentice-Hall Hispanoamericana, S.A,},
	year = {1993.},
	address = {México :},
	edition = {5.}
}