http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
11 pages including illustrations, tab., diagrams
by M. M. Leighton. Lower Ordovician and Cambrian oil possibilities in Illinois, by Stewart Folk.
At head of title: State of Illinois, Dept. of registration and education, Division of the State Geological Survey.
First article reprinted from the Oil weekly, March 13, 1944; second article reprinted from the Oil weekly, March 20, 1944.
Lower Ordovician and Cambrian oil possibilities in Illinois
Circular (Illinois State Geological Survey) ; 106