Não informado. (2004). Information Circular. Department of Natural Resources, Division of Geological Survey.
Cita Chicago Style (17a ed.)Não informado. Information Circular. Columbus, Ohio: Department of Natural Resources, Division of Geological Survey, 2004.
Cita MLA (8a ed.)Não informado. Information Circular. Department of Natural Resources, Division of Geological Survey, 2004.
Precaución: Estas citas no son 100% exactas.