@book{202620,
	author = {Billstein, Rick. and Libeskind, Shlomo.},
	title = {A problem solving approach to mathematics for elementary school teachers},
	publisher = {Addison-Wesley},
	year = {c2004.},
	address = {Boston},
	edition = {8th ed.},
	url = {http://www.loc.gov/catdir/toc/fy037/2002034364.html}
}