APA (7th ed.) Citation

Nilsen, T. H. (1993). Stratigraphy of the Cretaceous Hornbrook Formation, southern Oregon and northern California. U.S. Dept. of the Interior, U.S. Geological Survey.

Chicago Style (17th ed.) Citation

Nilsen, Tor Helge. Stratigraphy of the Cretaceous Hornbrook Formation, Southern Oregon and Northern California. [Reston, Va.]: U.S. Dept. of the Interior, U.S. Geological Survey, 1993.

MLA (9th ed.) Citation

Nilsen, Tor Helge. Stratigraphy of the Cretaceous Hornbrook Formation, Southern Oregon and Northern California. U.S. Dept. of the Interior, U.S. Geological Survey, 1993.