APA (7th ed.) Citation

Wisner, R. J., & Gertsma, J. M. (2005). Soil survey of Humboldt County, Iowa. U.S. Dept. of Agriculture, Natural Resources Conservation Service.

Chicago Style (17th ed.) Citation

Wisner, Robin J., and James M. Gertsma. Soil Survey of Humboldt County, Iowa. [Washington, D.C.]: U.S. Dept. of Agriculture, Natural Resources Conservation Service, 2005.

MLA (9th ed.) Citation

Wisner, Robin J., and James M. Gertsma. Soil Survey of Humboldt County, Iowa. U.S. Dept. of Agriculture, Natural Resources Conservation Service, 2005.