1. Argonne National Laboratory. “Users Handbook for the Argonne Premium Coal Sample Program.” Found at www.anl.gov.
2. Gaseous fuels, coal and coke,2003
3. The chemistry of coal. Coal Science and Technology, 7;Berkowitz,1985
4. The British Coal Utilization Research Association (BCURA) Coal Bank. Found at www.bcura.org.
5. International Organization for Standardization (ISO). Technical Committee 27, Subcommittee 5 (Solid Mineral Fuels). Found at www.iso.ch.