@book{27443,
	author = {Hatmaker, Paul Castleton, and Davis, Hubert Wesley,},
	title = {The fluorspar industry of the United States with special reference to Illinois-Kentucky district,},
	publisher = {Printed by authority of the state of Illinois,},
	year = {1938.},
	series = {Illinois. State geological survey. Bulletin},
	address = {Urbana, Ill.,},
	note = {In cooperation with the United States Department of the interior.  Bureau of mines.}
}