Não informado. (1972). Environmental Geology Report. Bureau of Topographic and Geologic Survey.
Chicago-viite (17. p.)Não informado. Environmental Geology Report. Harrisburg, Pa: Bureau of Topographic and Geologic Survey, 1972.
MLA-viite (8. p.)Não informado. Environmental Geology Report. Bureau of Topographic and Geologic Survey, 1972.
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