Johnson, D. L., & Airriess, C. A. (2010). World regional geography: A development approach (10th ed.). Prentice Hall.
Chicago-viite (17. p.)Johnson, Douglas L., ja Christopher A. Airriess. World Regional Geography: A Development Approach. 10th ed. New York: Prentice Hall, 2010.
MLA-viite (9. p.)Johnson, Douglas L., ja Christopher A. Airriess. World Regional Geography: A Development Approach. 10th ed. Prentice Hall, 2010.
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