Oregon. Department of Geology and Mineral Industries, Western Guide Publishers, & Preston, R. N. (1975). Oregon gold & gems maps: Then & now. Western Guide Publishers.
Style de citation Chicago (17e éd.)Oregon. Department of Geology and Mineral Industries, Western Guide Publishers, et Ralph N. Preston. Oregon Gold & Gems Maps: Then & Now. Corvallis [Or.]: Western Guide Publishers, 1975.
Style de citation MLA (8e éd.)Oregon. Department of Geology and Mineral Industries, et al. Oregon Gold & Gems Maps: Then & Now. Western Guide Publishers, 1975.
Attention : ces citations peuvent ne pas être correctes à 100%.