Orr, E. L., & Orr, W. L. (1996). Geology of the Pacific Northwest. McGraw-Hill.
Lua i Stíl Chicago (17ú heag.)Orr, Elizabeth L., agus William L. Orr. Geology of the Pacific Northwest. New York: McGraw-Hill, 1996.
Lua MLA (9ú heag.)Orr, Elizabeth L., agus William L. Orr. Geology of the Pacific Northwest. McGraw-Hill, 1996.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.