Cita APA (7th ed.)
Whitson, A. (1921). Soil Survey of Northern Wisconsin.
Cita Chicago (17th ed.)
Whitson, A.R. Soil Survey of Northern Wisconsin. Madison, 1921.
Cita MLA (9th ed.)
Whitson, A.R. Soil Survey of Northern Wisconsin. 1921.
Atenció: Aquestes cites poden no estar 100% correctes.