Accumulators	1
Agriculture	109
Analytical chemistry	5
Astronomy	20
Automated equipment	106
Aviation	6
Cables and cable production	5
Chemistry	173
Coal	34
Commerce	2
Communications	16
Computer numerical control	5
Computers	2
Construction	140
Criminal law	1
Cultural studies	1
Demography	1
Dyalysis	8
Earth sciences	311
Economics	12
Electric motors	2
Electric traction	2
Electrochemistry	2
Electronics	93
Energy industry	70
Environment	37
Finances	5
Fish farming pisciculture	3
Food industry	8
Forestry	5
Gear train	17
General	121
Health care	23
High energy physics	16
Hobbies and pastimes	2
Human rights activism	1
Immigration and citizenship	2
Industry	91
Information technology	40
International Monetary Fund	13
Isolation	1
Judo	4
Labor law	11
Law	14
Life sciences	71
Marketing	5
Materials science	74
Measuring instruments	52
Mechanic engineering	317
Mechanics	7
Medical	270
Medical appliances	117
Metallurgy	258
Meteorology	1
Microsoft	8
Municipal planning	28
Natural resourses and wildlife conservation	48
Natural sciences	43
Nuclear and fusion power	1
Nuclear physics	14
Obsolete / dated	1
Oil / petroleum	11
Packaging	38
Paragliding	2
Patents	4
Pest control	1
Physical sciences	28
Physics	5
Plastics	3
Plumbing	2
Politics	3
Radiation	14
Sailing	1
Scientific	1
Scuba diving	6
Social science	4
Sports	2
Swimming	1
Taxes	6
Technology	117
Telecommunications	3
Textile industry	29
Thermal Energy	3
Transport	438
Ultrasound	3