Keys to soil taxonomy /
by Soil Survey Staff.

APA Citation

United States. Natural Resources Conservation Service. (2003). Keys to soil taxonomy. Ninth edition. [Washington, D.C.]: U.S. Dept. of Agriculture, Natural Resources Conservation Service.

MLA Citation

United States. Natural Resources Conservation Service. Keys to Soil Taxonomy. Ninth edition. [Washington, D.C.]: U.S. Dept. of Agriculture, Natural Resources Conservation Service, 2003.

Warning: These citations may not always be complete (especially for serials).