Oberlander, T. M., & Muller, R. A. (1987). Essentials of physical geography today (2nd ed.). Random House.
Chicago-viite (17. p.)Oberlander, Theodore M., ja Robert A. Muller. Essentials of Physical Geography Today. 2nd ed. New York: Random House, 1987.
MLA-viite (9. p.)Oberlander, Theodore M., ja Robert A. Muller. Essentials of Physical Geography Today. 2nd ed. Random House, 1987.
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