Não informado. Soil management abstracts. International Board for Soil Research and Management.
Chicago-referens (17:e uppl.)Não informado. Soil Management Abstracts. Bangkok: International Board for Soil Research and Management.
MLA-referens (8:e uppl.)Não informado. Soil Management Abstracts. International Board for Soil Research and Management.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.