http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
I. Physiographic divisions of the area covered by the Illinoian drift-sheet in southern Illinois
II. Recent discoveries of Pre-Illinoian drift in southern Illinois
Pre-Illinoian drift in southern Illinois
Report of investigations (Illinois State Geological Survey) ; no. 19