Não informado. Topographic instructions of the United States Geological Survey. U.S. Department of the Interior.
Chicago-viite (17. p.)Não informado. Topographic Instructions of the United States Geological Survey. Washington: U.S. Department of the Interior.
MLA-viite (8. p.)Não informado. Topographic Instructions of the United States Geological Survey. U.S. Department of the Interior.
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