Material in the public domain. No restrictions on use.
Creative Commons License
This work has been identified with a Creative Commons Public Domain Mark 1.0.
Hoen, A. B.
"Discussion of the Requisite Qualities of Lithographic Limestone, with Report on Tests of the Lithographic Stone of Mitchell County, Iowa,"
Iowa Geological Survey Annual Report:
Available at: http://ir.uiowa.edu/igsar/vol13/iss1/9