@book{4510,
	author = {Osborn, Roger. and DeVault, M. Vere.},
	title = {Extending mathematics understanding},
	publisher = {C. E. Merrill Books , },
	year = {1961.},
	address = {Columbus, Ohio :},
	note = {Earlier ed. copyright 1960 under the titles Toward improved understanding of mathematics, part I and Toward improved understanding of mathematics, part II, by M. V. DeVault, published in 1960.}
}