@book{7771,
	author = {Billstein, Rick. and Libeskind, Shlomo.},
	title = {A problem solving approach to mathematics for elementary school teachers /},
	publisher = {Addison-Wesley,},
	year = {c1997.},
	address = {Reading, Mass. :},
	edition = {6th ed.},
	note = {Sixth ed. also published under title: A problem solving approach to mathematics.}
}