1. Spectrochemical analyses of coal ash for trace elements;Abernathy;U.S. Dep. Inter. Bur. Mines, Rep. Invest. 7281,1969
2. Metal-content genetic types of coals from some deposits of Transbaikalia;Admakin;Dokl. Akad. Nauk SSSR,1974
3. Rare elements in the coal formations;Baranov,1966
4. The distribution and origin of minor elements in coal;Bethell;Br. Coal. Util. Res. Assoc. Mon. Bull.,1962
5. Trace elements in the rocks and the coals from the low Mesozoic sediments of the Maikjubin basin and their paleogeographical significance;Buvalkin;Izv. Akad. Nauk Kazach. SSR, Geologia,1963