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2. ASTM Standard D2797/D2797M-11a, 2011. Standard Practice for Preparing Coal Samples for Microscopical Analysis by Reflected Light. ASTM International, West Conshohocken, PA (2011).
3. ASTM Standard D3173-11, 2011. Test Method for Moisture in the Analysis Sample of Coal and Coke. ASTM International, West Conshohocken, PA.
4. ASTM Standard D3174-11, 2011. Annual Book of ASTM Standards. Test Method for Ash in the Analysis Sample of Coal and Coke. ASTM International, West Conshohocken, PA.
5. ASTM Standard D3175-11, 2011. Test Method for Volatile Matter in the Analysis Sample of Coal and Coke. ASTM International, West Conshohocken, PA.