@book{26917,
	author = {Bradley, Wilmot Hyde,},
	title = {Origin and microfossils of the oil shale of the Green River formation of Colorado and Utah,},
	publisher = {U.S. Govt. Print. Off.,},
	year = {1931.},
	series = {U. S.  Geological Survey.  Professional paper 168},
	address = {Washington,},
	note = {At head of title: United States Department of the Interior.}
}