APA (7th ed.) Citation

United States. Soil Conservation Service. (1994). Keys to Soil Taxonomy (6th ed.). United States Dept. of Agriculture, Soil Conservation Service.

Chicago Style (17th ed.) Citation

United States. Soil Conservation Service. Keys to Soil Taxonomy. 6th ed. [Washington, D.C.]: United States Dept. of Agriculture, Soil Conservation Service, 1994.

MLA (9th ed.) Citation

United States. Soil Conservation Service. Keys to Soil Taxonomy. 6th ed. United States Dept. of Agriculture, Soil Conservation Service, 1994.