1. Characterization of the quality of coals from the Illinois Basin, Chapter E;Affolter,2002
2. Bragg, L.J., Oman, J.K., Tewalt, S.J., Oman, C.L., Rega, N.H., Washington, P.M., Finkelman, R.B., 1997. U.S. Geological Survey Coal Quality (COALQUAL) database; version 2.0, U.S.
3. Geology and coal resources of the coal-bearing rocks of Alabama;Culbertson;U.S. Geological Survey Bulletin,1964
4. Mineralogic residence and sequence of emplacement of arsenic and other trace elements in coals of the Warrior Basin, Alabama;Diehl,2002
5. Trace-metal sources and their release from mine wastes; Examples from humidity cell tests of hard-rock mine waste and from Warrior Basin coal;Diehl,2003