Não informado. (2004). Environmental geology notes. Illinois State Geological Survey.
Style de citation Chicago (17e éd.)Não informado. Environmental Geology Notes. Naperville, Ill: Illinois State Geological Survey, 2004.
Style de citation MLA (8e éd.)Não informado. Environmental Geology Notes. Illinois State Geological Survey, 2004.
Attention : ces citations peuvent ne pas être correctes à 100%.