Press, F., & Siever, R. (1974). Earth. W. H. Freeman.
Cita Chicago (17th ed.)Press, Frank, i Raymond Siever. Earth. San Francisco: W. H. Freeman, 1974.
Cita MLA (9th ed.)Press, Frank, i Raymond Siever. Earth. W. H. Freeman, 1974.
Atenció: Aquestes cites poden no estar 100% correctes.