Não informado. Tropical Soils Research Program, Annual Report. North Carolina State University, Soil Science Department.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Tropical Soils Research Program, Annual Report. Raleigh, NC: North Carolina State University, Soil Science Department.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Tropical Soils Research Program, Annual Report. North Carolina State University, Soil Science Department.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.