@book{411,
	author = {Khanna, V.K.},
	title = {Digital Communication /},
	publisher = {S Chand & Co Ltd,},
	year = {2011.},
	address = {New Delhi :},
	edition = {2nd ed.},
	url = {http://www.amazon.com/exec/obidos/ASIN/8121931029/chopaconline-20}
}