Não informado. (2004). Information Circular. Department of Natural Resources, Division of Geological Survey.
Style de citation Chicago (17e éd.)Não informado. Information Circular. Columbus, Ohio: Department of Natural Resources, Division of Geological Survey, 2004.
Style de citation MLA (8e éd.)Não informado. Information Circular. Department of Natural Resources, Division of Geological Survey, 2004.
Attention : ces citations peuvent ne pas être correctes à 100%.