http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Research Program on Soils of the Tropics, Annual Report
Agronomic-Economic Research on Soils of the Tropics
North Carolina State University, Soil Science Department
Empresa Brasileira de Pesquisa Agropecuária Centro de Pesquisa Agroflorestal da Amazônia Oriental