@book {23821,
	title = {Umpqua River Gravel Study},
	year = {1971},
	note = {"for the Umpqua River Navigation Company."  Report on a six-mile stretch downstream from Scottsburg to determine whether natural deposits of gravel are naturally replenished after gravel commercially extracted. },
	month = {1971, June},
	chapter = {22 p.},
	address = {Eugene, Or.},
	keywords = {geology, human impacts, industrial development, mining, sediments, water quality}
}
