1. Petrology of Oligocene coal, Makum coalfield, Assam, Northeast India;Ahmed;Int. J. Coal Geol.,1996
2. The Statistical Analysis of Compositional Data;Aitchison,1986
3. Standard Methods for the Examining of Waste and Wastewater, 20th Ed;APHA,1998
4. ASTM, Manual on Presentation of Data and Control Chart Analyses;ASTM,1991
5. Annual Book of ASTM Standards; Gaseous Fuels; Coal and Coke; Bioenergy and Industrial Chemicals from Biomass;ASTM,2013