1. Bituminous Coal Fields of Pennsylvania;Ashley,1928
2. D3176-89(2002) Standard Practice for Ultimate Analysis of Coal and Coke,2002
3. D388-05 Standard Classification of Coals by Rank,2005
4. D3172-07A Standard Practice for Proximate Analysis of Coal and Coke,2007
5. Spontaneous Combustion of Coal and Mine Fires;Banerjee,1985