APA (7e ed.) Bronvermelding

Orr, E. L., & Orr, W. L. (1996). Geology of the Pacific Northwest. McGraw-Hill.

Chicago (17e ed.) Bronvermelding

Orr, Elizabeth L., en William L. Orr. Geology of the Pacific Northwest. New York: McGraw-Hill, 1996.

MLA (9e ed.) Bronvermelding

Orr, Elizabeth L., en William L. Orr. Geology of the Pacific Northwest. McGraw-Hill, 1996.