Παραπομπή APA

Soil survey staff. (1990). Keys to soil taxonomy. Blacksburg, Va: Virginia Polytechnic Institute and State University.

Παραπομπή Chicago Style

Soil survey staff. Keys to Soil Taxonomy. Blacksburg, Va: Virginia Polytechnic Institute and State University, 1990.

Παραπομπή MLA

Soil survey staff. Keys to Soil Taxonomy. Blacksburg, Va: Virginia Polytechnic Institute and State University, 1990.

Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.