1. A Framework for Land Evaluation.Soils Bulletin; Food and Agricultural Organization (FAO): Rome, 1976; 1–32.
2. Towards a minimum data set to assess soil organic matter quality in agricultural soils
3. Bouma, J.Land evaluation for landscape units. InHand-Book of Soil Science; Sumner, M.E., Ed.; CRC Press: Boca Raton, 2000; E-393–E-412.