1. Technology of Lignitic Coals;U.S. Bureau of Mines;U.S. Bur. Mines Inf. Circ.,1954
2. Cellulose from hardwood;Richter;Ind. Eng. Chem.,1941
3. Silicified lignite from the Tertiary of south-central Saskatchewan;Broughton;Can. J. Earth Sci.,1976
4. Late Tertiary silicified wood in the Rosenback coal seams near Latschach, Lake Faaker;Hoehne;Carinthia, Geologie,1953
5. The origin, occurrence, and distribution of the inorganic constituents in low-rank coals;Finkleman,1982