APA (7th ed.) Citation

Soil Survey Staff. (2006). Keys to soil taxonomy (10a. ed.). United States Department of Agriculture. Natural Resources Conservation Service.

Chicago Style (17th ed.) Citation

Soil Survey Staff. Keys to Soil Taxonomy. 10a. ed. Washington, D.C: United States Department of Agriculture. Natural Resources Conservation Service, 2006.

MLA (9th ed.) Citation

Soil Survey Staff. Keys to Soil Taxonomy. 10a. ed. United States Department of Agriculture. Natural Resources Conservation Service, 2006.