TY  - CPAPER
AU  - I. Kostova
TI  - TRACE ELEMENTS IN SULPHIDE AND SULPHATE MINERALS IN COAL AND THEIR ENVIRONMENTAL IMPACT
T2  - 3rd International Scientific Conference - SGEM2003
PY  - 2003
SP  - 27
EP  - 28
PB  - SGEM Scientific GeoConference
ER  -