@book{13119,
	author = {Lamon, Susan J.,},
	title = {Teaching fractions and ratios for understanding :},
	publisher = {Erlbaum,},
	year = {1999.},
	address = {Mahwah, N.J. :},
	url = {http://www.loc.gov/catdir/enhancements/fy0745/98051379-d.html}
}