1. Study of the association of minor elements with the organic and the inorganic fraction of coal from Leas mine;Azambuja;Min. Metall.,1981
2. Paleoenvironment and sulfur-boron contents of the Mannville (Lower Cretaceous) coals of southern Alberta, Canada;Banerjee,1990
3. The petrography, mineralogy and geochemistry of a Paleocene lignite from southern Saskatchewan, Canada;Beaton;Int. J. Coal. Geol.,1991
4. Inorganic constituents in low rank coals—direct coal analysis or ash analysis?;Benson,1984
5. Inorganic constituents of Australian coals, part 1: nature and modes of occurrence;Brown;J. Inst. Fuel,1964