@book{72585,
	author = {Michael R. Ziegler},
	title = {Precalculus /},
	publisher = {McGraw-Hill,},
	year = {2011.},
	series = {Barnett, Ziegler & Byleen's precalculus series},
	address = {Dubuque, IA :},
	edition = {7th ed.},
	note = {Includes index.}
}