@book{147235,
	author = {Chen, Chi-Tsong, },
	title = {Signals and systems },
	publisher = {Oxford University Press, },
	year = {2004.},
	series = { The Oxford series in electrical and computer engineering},
	address = {Oxford.:},
	edition = {3a ed.},
	note = {Ed. rev. de: System and signal analysis. 2nd ed. c1994}
}