APA (7th ed.) Citation

Illinois State Geological Survey & Bargh, M. H. (1989). Illinois coal mines, Clay County. Illinois State Geological Survey.

Chicago Style (17th ed.) Citation

Illinois State Geological Survey and Margaret H. Bargh. Illinois Coal Mines, Clay County. [Champaign, Ill.]: Illinois State Geological Survey, 1989.

MLA (8th ed.) Citation

Illinois State Geological Survey and Margaret H. Bargh. Illinois Coal Mines, Clay County. Illinois State Geological Survey, 1989.