Prehistory of the Lower Columbia and Willamette Valley, by Richard Pettigrew, in Handbook of North American Indians, Volume 7, Northwest Coast (1990), Smithsonian Institution.

Columbia River Trade Network, by Theodore Stern, in Handbook of North American Indians, Volume 12, Plateau, (1998), Smithsonian Institution.

Indian Rock Art of the Columbia Plateau, by James D. Keyser, University of Washington Press, Seattle (1992).

Nich-i-wana “The Big River,” by Eugene Hunn, University of Washington Press, Seattle (1990)