Não informado. (1883). Bulletin of the United States Geological Survey. U.S. Department of the Interior.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Bulletin of the United States Geological Survey. Washington: U.S. Department of the Interior, 1883.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Bulletin of the United States Geological Survey. U.S. Department of the Interior, 1883.
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