@book{716,
	author = {Blake, Roy},
	title = {Digital & analog communication systems 7ed.},
	publisher = {PHI LEARNING PVT LTD,},
	year = {2008.},
	address = {[S.l.] :},
	edition = {7th ed.},
	url = {http://www.amazon.com/exec/obidos/ASIN/8120334116/chopaconline-20}
}