Address: University of Mining and Geology „St. Ivan Rilski“, Faculty of Geology and Prospecting, Department of Mineralogy and Petrography, Sofia 1700; rikostov@yahoo.com Tel.: (+359 2)8060385; 0889180137
Address: Geological Institute, Bulgarian Academy of Sciences; “Acad. Georgi Bonchev” Str., bl. 24; 1113 Sofia; Scientific Secretary of the Institute; radi@geology.bas.bg Tel: (+359 2)9792207
Address: Geological Institute, Bulgarian Academy of Sciences; “Acad. Georgi Bonchev” Str., bl. 24; 1113 Sofia; rosivas10@yahoo.com Tel: (+359 2) 9792273
Address: National Museum “Earth and Man” ; 4 “Cherni Vrah” Blvd., 1421 Sofia; larisanesheva@abv.bg
Tel: (+359 2) 8661456
Address: Sofia University “St. Kliment Ohridski”; Faculty of Geology and Geography; Department of Mineralogy, Petrology and Economic Geology; 15 “Tsar Osvoboditel” Blvd., 1504 Sofia; kamen@gea.uni-sofia.bg
Tel: (+359 2)9308256