DIXON, D. Encyclopedia Of Science: The Earth Our Planet Its Land, Sea, and Air. Macmillan Publishing Company.
Chicago-referens (17:e uppl.)DIXON, Dougal. Encyclopedia Of Science: The Earth Our Planet Its Land, Sea, and Air. Macmillan Publishing Company.
MLA-referens (8:e uppl.)DIXON, Dougal. Encyclopedia Of Science: The Earth Our Planet Its Land, Sea, and Air. Macmillan Publishing Company.
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