Cita APA (7th ed.)

Sumner, R. (2004). Geography basics. Salem Press.

Cita Chicago (17th ed.)

Sumner, Ray. Geography Basics. Pasadena, Calif.: Salem Press, 2004.

Cita MLA (9th ed.)

Sumner, Ray. Geography Basics. Salem Press, 2004.

Atenció: Aquestes cites poden no estar 100% correctes.