@book {23471,
	title = {Geologic map of the Lower Umpqua River area, Oregon [cartographic material]},
	series = {Geological Survey (U.S.). Oil and Gas Investigations},
	number = {OM-204.},
	year = {1961},
	note = {It is possible to download previewed sections of the map.},
	month = {1961},
	publisher = {The Survey},
	organization = {The Survey},
	address = {Washington, D.C},
	keywords = {geology, Lower Umpqua River, maps},
	doi = {https://doi.org/10.3133/om204 },
	url = {https://ngmdb.usgs.gov/Prodesc/proddesc_5358.htm},
	author = {Baldwin, Ewart Merlin}
}
