@book{145911,
	author = {Bernknopf, Richard L. and National Geologic Mapping Program U.S.},
	title = {Societal value of geologic maps},
	publisher = {U.S. G.P.O.},
	year = {1993.},
	series = {U.S. Geological Survey circular},
	address = {[Washington, D.C.]},
	note = {"An economic analysis by the U.S. Geological Survey's National Geologic Mapping Program that describes (1) geologic maps and their use as a fundamental data base, (2) a rigorous benefit-cost model for valuing geologic map information, and (3) the economic issues associated with determining whether or not a geologic map is a public good."}
}