He was from the intelligentsia class, and had an impressive education in geology and nuclear geophysics and published many scientific papers.
2.
Dobrev studied geophysics in Sofia and then worked as an engineer at the Laboratory for underground nuclear geophysics and geochemistry ( Bulgarian : 01 > @ 0B > @ 8O ? > ? > 475 < = 0 8 O4 @ 5 = 0 35 > D878 : 0 8 35 > E8 < 8O ).