@book{145513,
	author = {Nilsen, Tor Helge.},
	title = {Stratigraphy of the Cretaceous Hornbrook Formation, southern Oregon and northern California},
	publisher = {U.S. G.P.O.},
	year = {1993.},
	series = {U.S. Geological Survey professional paper},
	address = {Washington},
	note = {One map on folded leaf in pocket.}
}