Cita APA (7th ed.)

Readers Digest Asso. (1980). Natural wonders of the world. RDA.

Cita Chicago (17th ed.)

Readers Digest Asso. Natural Wonders of the World. New York: RDA, 1980.

Cita MLA (9th ed.)

Readers Digest Asso. Natural Wonders of the World. RDA, 1980.