Cita APA (7th ed.)

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.