1. Major Ash Constituents in U.S. Coals;Abernethy,1969
2. Composition and Origin of Mineral Matter in Coal;Thiessen,1945
3. Elemental Ash Distribution in Coal Components — Use of Electron Probe;Dutcher,1964
4. Organically Bound Iron in Brown Coal;Shaffer;Fuel,1977
5. Chemistry of Brown Coal II. Infrared Spectroscopic Studies;Brooks;Australian Journal of Applied Science,1958