@book{12049,
	author = {Penna, Judith A.},
	title = {Graphing calculator manual /},
	publisher = {Pearson/Addison-Wesley,},
	year = {c2009},
	address = {Boston :},
	note = {"Algebra and trigonometry graphs & models and Precalculus graphs & models fourth edition / Marvin L. Bittinger, Judith A Beecher, David J. Ellenbogen, Judith A Penna."},
	url = {http://www.loc.gov/catdir/toc/fy0805/2008271773.html}
}