@book{93973,
	author = {Freudenthal, Hans and International Union of the History and Philosophy of Science.},
	title = {The Concept and the role of the model in mathematics and natural and social sciences},
	publisher = {D. Reidel Pub. Co.},
	year = {[c1961]},
	series = {Synthese library.},
	address = {Dordrecht},
	note = {English, French or German.}
}