Não informado. (2011). Geological Survey Bulletin. U.S. Department of the Interior, Geological Survey.
Chicago-viite (17. p.)Não informado. Geological Survey Bulletin. Washington: U.S. Department of the Interior, Geological Survey, 2011.
MLA-viite (8. p.)Não informado. Geological Survey Bulletin. U.S. Department of the Interior, Geological Survey, 2011.
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