Thoman, R. S. (1964). Focus on geographic activity: A collection of original studies/ by. McGraw-Hill.
Chicago-viite (17. p.)Thoman, Richard S. Focus on Geographic Activity: A Collection of Original Studies/ by. New York: McGraw-Hill, 1964.
MLA-viite (9. p.)Thoman, Richard S. Focus on Geographic Activity: A Collection of Original Studies/ by. McGraw-Hill, 1964.
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