aan achterzijde bevestigde beveiligingsboog

Accounting	14
Agriculture	118
Art	3
Automated equipment	13
Aviation	1
Business	4
Chemistry	52
Coal	9
Commerce	8
Communications	111
Computer numerical control	2
Construction	32
Criminal law	4
Cultural studies	9
Customs	3
Demography	7
Earth sciences	37
Ecology	1
Economics	144
Education	18
Electronics	84
Employment	2
Energy industry	18
Environment	137
Finances	244
Fish farming pisciculture	4
Food industry	6
General	367
Geography	1
Health care	97
Hobbies and pastimes	9
Human rights activism	9
Immigration and citizenship	25
Industry	50
Information technology	59
Insurance	38
International trade	5
Labor law	40
Labor organization	1
Law	307
Life sciences	27
Marketing	56
Materials science	23
Mathematics	7
Measuring instruments	4
Mechanic engineering	59
Medical	89
Metallurgy	40
Microsoft	41
Mineral products	4
Municipal planning	5
Natural resourses and wildlife conservation	1
Natural sciences	32
Nuclear and fusion power	1
Nuclear physics	2
Obsolete / dated	8
Oil / petroleum	1
Patents	16
Pharmacy and pharmacology	8
Physical sciences	1
Politics	41
Procedural law	5
Research and development	2
Scientific	3
Security systems	2
Social science	38
Sociology	3
Statistics	37
Taxes	23
Technology	23
Transport	221
United Nations	8
Work flow	6