Rights
Material in the public domain. No restrictions on use.
Recommended Citation
Olin, H. L. and Troeltzsch, J. R. (1924) "The Distribution of Ash and Sulfur in Iowa Coals as Affected by Washing and Flotation," Iowa Geological Survey Annual Report: Vol. 31: p. 153-166.Available at: http://ir.uiowa.edu/igsar/vol31/iss1/6