APA (7th ed.) Citation

Smith, D., & Wilson, A. (1999). The state of the world atlas (New rev. 6th ed.). Penguin Reference.

Chicago Style (17th ed.) Citation

Smith, Dan, and Angela Wilson. The State of the World Atlas. New rev. 6th ed. London ; New York: Penguin Reference, 1999.

MLA (9th ed.) Citation

Smith, Dan, and Angela Wilson. The State of the World Atlas. New rev. 6th ed. Penguin Reference, 1999.