Cita APA (7th ed.)

Canby, T. Y. (1994). Our changing earth. National Geographic Society.

Cita Chicago (17th ed.)

Canby, Thomas Y. Our Changing Earth. Washington, D.C: National Geographic Society, 1994.

Cita MLA (9th ed.)

Canby, Thomas Y. Our Changing Earth. National Geographic Society, 1994.