@book{133646,
	author = {Kramer, Klaas},
	title = {Teaching elementary school mathematics / },
	publisher = {Allyn and Bacon,},
	year = {[1978].},
	address = {Boston:},
	edition = {4th ed.},
	note = {First ed. published in 1966 under title: The teaching of elementary school mathematics.}
}