@book{63558,
	author = {Koopmans, Tjalling Charles},
	title = {Three essays on the state of economic science},
	publisher = {A.M. Kelley},
	year = {[1991]},
	series = {Reprints of economic classics},
	address = {Fairfield, NJ},
	note = {Originally published: New York : McGraw-Hill, 1957.}
}