Não informado. (1954). Virginia minerals. Department of Conservation and Development, Division of Geology.
Chicago-viite (17. p.)Não informado. Virginia Minerals. Charlottesville, Va: Department of Conservation and Development, Division of Geology, 1954.
MLA-viite (8. p.)Não informado. Virginia Minerals. Department of Conservation and Development, Division of Geology, 1954.
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