Não informado. Tropical Soils Research Program, Annual Report. North Carolina State University, Soil Science Department.
Chicago-referens (17:e uppl.)Não informado. Tropical Soils Research Program, Annual Report. Raleigh, NC: North Carolina State University, Soil Science Department.
MLA-referens (8:e uppl.)Não informado. Tropical Soils Research Program, Annual Report. North Carolina State University, Soil Science Department.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.