1. ASTM D2492-02, 2012. Standard Test Method for Forms of Sulfur in Coal. ASTM International, West Conshohocken, PA. www.astm.org.
2. Standard Test Method for Microscopical Determination of Vitrinite Reflectance of Coal;ASTM D2798-11a;ASTM International,2011
3. ASTM D3173/D3173M-17a, 2017. Standard Test Method for Moisture in the Analysis Sample of Coal and Coke. ASTM International, West Conshohocken, PA. www.astm. org.
4. ASTM D3174-12, 2012. Standard Test Method for Ash in the Analysis Sample of Coal and Coke from Coal, ASTM International, West Conshohocken, PA, 2012, www.astm.org.
5. ASTM D3175-17,2017. Standard Test Method for Volatile Matter in the Analysis Sample of Coal and Coke, ASTM International, West Conshohocken, PA, 2017, www.astm.org.