Cita APA

(1998). KEYS to Soil Taxonomy (8.ed.). Washington: USDA-NRCS.

Citación estilo Chicago

KEYS to Soil Taxonomy. 8.ed. Washington: USDA-NRCS, 1998.

Cita MLA

KEYS to Soil Taxonomy. 8.ed. Washington: USDA-NRCS, 1998.