Não informado. (2016). Research Program on Soils of the Tropics, Annual Report. North Carolina State University, Soil Science Department.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Research Program on Soils of the Tropics, Annual Report. Raleigh, NC: North Carolina State University, Soil Science Department, 2016.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Research Program on Soils of the Tropics, Annual Report. North Carolina State University, Soil Science Department, 2016.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.