SOPHER, C. D. Soils and soil management. (2nd ed.). c1980.
Cita Chicago (17th ed.)SOPHER, Charles D. Soils and Soil Management. 2nd ed. Virgi-nia: c1980.
Cita MLA (9th ed.)SOPHER, Charles D. Soils and Soil Management. 2nd ed. c1980.
Atenció: Aquestes cites poden no estar 100% correctes.