@book{41083,
	author = {Heuvel-Panhuizen, Marja van den,},
	title = {Children Learn Mathematics :},
	publisher = {Brill | Sense,},
	year = {2008.},
	series = {Dutch Design in Mathematics Education ;},
	address = {Leiden; },
	url = {http://dx.doi.org/10.1163/9789087903954}
}