1. Coal weathering: causes, effects and implications;Cox;Pre. Pa.-Am. Chem. Soc. Div. Fuel Chem.,1984
2. Natural oxidation of coal;Davidson;IEA Coal Research,1990
3. C.R. Nelson (Ed.), Chemistry of Coal Weathering, Coal Science and Technology, Vol. 14, Elsevier, Amsterdam, 1989.
4. Effects of natural weathering and low temperature oxidation on some aspects of the combustion behaviour of bituminous coals;Pisupati;Fuel,1993
5. C. Romero, J.L. Miranda, Oxidación y autocombustión de carbones en parque, 5° Informe, Proyecto 5th Report ECSC 7220-EA/752, December 1991.