United States Department of Agriculture, & Natural Resources Conservation Service. (1996). Soil survey methods manual: The soil survey analytical continuum. Lincoln: National Soil Survey Center.
Παραπομπή Chicago StyleUnited States Department of Agriculture, και Natural Resources Conservation Service. Soil Survey Methods Manual: The Soil Survey Analytical Continuum. Lincoln: National Soil Survey Center, 1996.
Παραπομπή MLAUnited States Department of Agriculture, και Natural Resources Conservation Service. Soil Survey Methods Manual: The Soil Survey Analytical Continuum. Lincoln: National Soil Survey Center, 1996.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.