@book{199504,
	author = {Varberg, Dale E., and Purcell, Edwin J.,},
	title = {Calculus /},
	publisher = {Pearson Prentice Hall, },
	year = {2007},
	address = {Upper Saddle River, New Jersey :},
	edition = {NINTH EDITION},
	note = {Includes exercises and answers

}
}