@book{31949,
	author = {Oppenheim, Alan V., and Willsky, Alan S.},
	title = {Signals and systems /},
	publisher = {Prentice-Hall,},
	year = {2014},
	address = {Englewood Cliffs, N.J. :},
	edition = {2nd ed},
	note = {Includes index.}
}