Não informado. (1931). Geological Bulletin. Department of Conservation, Geological Survey.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Geological Bulletin. New Orleans, La: Department of Conservation, Geological Survey, 1931.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Geological Bulletin. Department of Conservation, Geological Survey, 1931.
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