1. American Society for Testing and Materials (2011) ASTM D 2013-10/D2013M-11 Standard Practice for Preparing Coal Samples for Analysis
2. American Society for Testing and Materials (2009) ASTM D 3176-09 Standard Practice for Ultimate Analysis of Coal and Coke
3. American Society for Testing and Materials (2008) ASTM D 5373-08 Standard Test Methods for Instrumental Determination of Carbon, Hydrogen, and Nitrogen in Laboratory Samples of Coal and Coke
4. American Society for Testing and Materials (2010) ASTM D 5865-10 Standard Test Method for Gross Calorific Value of Coal and Coke
5. British Petroleum (2011) BP statistical review of world energy