APA (7th ed.) Citation

O'Connor, T. (1990). Soil survey of Sioux County, Iowa. The Service.

Chicago Style (17th ed.) Citation

O'Connor, Thomas. Soil Survey of Sioux County, Iowa. [Washington, D.C.?]: The Service, 1990.

MLA (9th ed.) Citation

O'Connor, Thomas. Soil Survey of Sioux County, Iowa. The Service, 1990.