@book{80456,
	author = {Haykin, Simon S and Veen, Barry Van},
	title = {Signals and systems. (2nd edition)},
	publisher = {Wiley},
	year = {2003},
	address = {New Jersey},
	edition = {2nd edition},
	note = {Includes index.},
	url = {http://www.loc.gov/catdir/description/wiley0310/2002027040.html}
}