http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Contributions to the stratigraphy of Illinois
by Stuart Weller. Lower Paleozoic stratigraphy of southwestern Illinois, by T. E. Savage. Notes on Shoal Creek limestone, by Jon Udden.
Lower Paleozoic stratigraphy of southwestern Illinois
Bulletin (Illinois State Geological Survey) ; no. 8