@book{27173,
	author = {Ross, Clarence Samuel,},
	title = {Origin of the copper deposits of the Ducktown type in the southern Appalachian region /},
	publisher = {U.S. Gov't. Print. Off.,},
	year = {1935},
	series = {Geological Survey (U.S.). Geological Survey professional paper ;},
	address = {Washington :},
	note = {At head of title:  United States Department of the Interior.}
}