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3. ASTM Standard D3174-12 (2018a) Annual book of ASTM standards. Test method for ash in the analysis sample of coal and coke. ASTM International, West Conshohocken, PA
4. ASTM Standard D3175-18 (2018b) Test method for volatile matter in the analysis sample of coal and coke. ASTM International, West Conshohocken, PA
5. ASTM Standard D4239-18e1 (2018c) Standard test method for sulfur in the analysis sample of coal and coke using high-temperature tube furnace combustion. ASTM International, West Conshohocken, PA