1. Abhishek R, Tiwary K, Sinha SK (2006) Status of surface and groundwater quality in coal mining and industrial areas of Jharia coalfield. Ind J Environ Prot 26:905–910
2. Ahmed M, Rahim A (1996) Abundance of sulfur in Eocene coal beds from Bapung, Northeast India. Int J Coal Geolgy 30:315–318
3. Banerjee NN, Ghosh B, Das A (2000) Trace metals in Indian Coals; CFRI golden jubilee monograph. Allied Publishers Ltd, New Delhi, p 13
4. Baruah BP (2009) Environmental studies around makum coalfields. LAP Lambert Academic Publishing, India
5. Baruah BP, Khare P (2007a) Pyrolysis of high sulfur Indian coals. Energy Fuels 21:3346–3352