@book{37854,
	author = {Allen, G. Donald,},
	title = {Pedagogy and Content in Middle and High School Mathematics /},
	publisher = {Brill | Sense,},
	year = {2017.},
	series = {Educational Research E-Books Online, Collection 2005-2017, ISBN: 9789004394001},
	address = {Leiden, },
	url = {http://dx.doi.org/10.1007/978-94-6351-137-7}
}