Não informado. Soil management abstracts. International Board for Soil Research and Management.
Chicago-viite (17. p.)Não informado. Soil Management Abstracts. Bangkok: International Board for Soil Research and Management.
MLA-viite (8. p.)Não informado. Soil Management Abstracts. International Board for Soil Research and Management.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.