1. The redistribution of trace elements during the beneficiation of coal, Chapter 6;Akers,1995
2. ASTM D2013/D2013M-12, Standard Practice for Preparing Coal Samples for Analysis;ASTM International,2019
3. ASTM D3172-13, Standard Practice for Proximate Analysis of Coal and Coke;ASTM International,2019
4. ASTM D3176-15, Standard Practice for Ultimate Analysis of Coal and Coke;ASTM International,2019
5. ASTM D2492-02(2012), Standard Test Method for Forms of Sulfur in Coal;ASTM International,2019