APA (7th ed.) Citation

Frey, R. C. (1995). Middle and Upper Ordovician nautiloid cephalopods of the Cincinnati arch region of Kentucky, Indiana, and Ohio. U.S. Department of the Interior, U.S. Geological Survey.

Chicago Style (17th ed.) Citation

Frey, Robert C. Middle and Upper Ordovician Nautiloid Cephalopods of the Cincinnati Arch Region of Kentucky, Indiana, and Ohio. Washington: U.S. Department of the Interior, U.S. Geological Survey, 1995.

MLA (9th ed.) Citation

Frey, Robert C. Middle and Upper Ordovician Nautiloid Cephalopods of the Cincinnati Arch Region of Kentucky, Indiana, and Ohio. U.S. Department of the Interior, U.S. Geological Survey, 1995.