1. Mineral Matter in Coal,1986
2. Mineral Impurities in Coal Combustion;Raask,1985
3. Coal ash—its effect on combustion systems;Reid,1981
4. Potash from wood and plant ashes;Bradley;Metall. Chem. Eng.,1915
5. Agricultural use of wood ash as a fertilizer and liming material;Naylor;Tappi,1986