APA (7th ed.) Citation

Koppen, M. P., & Worster, J. R. (1979). Soil survey of Sac County, Iowa. The Service.

Chicago Style (17th ed.) Citation

Koppen, Maynard P., and John R. Worster. Soil Survey of Sac County, Iowa. [Washington, D.C.]: The Service, 1979.

MLA (9th ed.) Citation

Koppen, Maynard P., and John R. Worster. Soil Survey of Sac County, Iowa. The Service, 1979.