@book{11627,
	author = {Billstein, Rick. and Libeskind, Shlomo.},
	title = {A problem solving approach to mathematics for elementary school teachers /},
	publisher = {Pearson Addison Wesley,},
	year = {c2007.},
	address = {Boston :},
	edition = {9th ed.},
	note = {Includes index.}
}