@book{24608,
	author = {Butts, Charles,},
	title = {Economic geology of the Kittanning and Rural valley quadrangles, Pennsylvania,},
	publisher = {Govt. print. off.,},
	year = {1906.},
	series = {U.S. Geological survey. Bulletin},
	address = {Washington,},
	note = {Subject series: A, Economic geology, 67; B, Descriptive geology, 83.}
}