Oregon. Department of Geology and Mineral Industries, Western Guide Publishers, & Preston, R. N. (1975). Oregon gold & gems maps: Then & now. Western Guide Publishers.
Cita Chicago Style (17a ed.)Oregon. Department of Geology and Mineral Industries, Western Guide Publishers, y Ralph N. Preston. Oregon Gold & Gems Maps: Then & Now. Corvallis [Or.]: Western Guide Publishers, 1975.
Cita MLA (8a ed.)Oregon. Department of Geology and Mineral Industries, et al. Oregon Gold & Gems Maps: Then & Now. Western Guide Publishers, 1975.
Precaución: Estas citas no son 100% exactas.