VOLUME 46 (2)/November 2017 125th Anniversary of Acad. Strashimir Dimitrov;
70th Anniversary of the Geological Institute, Bulgarian Academy of Sciences
University of Mining and Geology, Department of Geology and Geoinformatics, Studentski Grad, Prof. Boyan Kamenov Str., 1700 Sofia, Bulgaria; Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria
Comenius University, Faculty of Natural Sciences, Department of Geology and Palaeontology, Mlynská dolina G–229, Ilkovičova 6, SK-84215 Bratislava, Slovak Republic
Faculty of Geology and Geography, Department of Geology, Palaeontology and Fossil Fuels, Sofia University “St Kliment Ohridski, 15 Tsar Osvoboditel Blvd, 1504 Sofia, Bulgaria
Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev, Bl. 24, 1113 Sofia, Bulgaria; Institute of Geochemistry and Petrology, ETH, 8092 Zurich, Switzerland