Não informado. (1966). Abstracts of North American geology. U.S. Geological Survey.
Chicago-viite (17. p.)Não informado. Abstracts of North American Geology. Washington: U.S. Geological Survey, 1966.
MLA-viite (8. p.)Não informado. Abstracts of North American Geology. U.S. Geological Survey, 1966.
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