| Accounting | 47 |
| Agriculture | 539 |
| Animal husbandry | 11 |
| Antennas and waveguides | 86 |
| Art | 2 |
| Astronautics | 5 |
| Automatic control | 25 |
| Banking | 3 |
| Business | 1 |
| Cables and cable production | 35 |
| Chemistry | 460 |
| Coal | 19 |
| Commerce | 35 |
| Communications | 903 |
| Construction | 185 |
| Corporate governance | 3 |
| Criminal law | 27 |
| Cultural studies | 11 |
| Customs | 1 |
| Data processing | 1 |
| Demography | 5 |
| Earth sciences | 490 |
| Ecology | 10 |
| Economics | 181 |
| Education | 17 |
| Electric machinery | 18 |
| Electric motors | 44 |
| Electrical engineering | 30 |
| Electricity generation | 13 |
| Electronics | 1281 |
| Employment | 8 |
| Energy industry | 84 |
| Environment | 206 |
| Finances | 379 |
| Fish farming pisciculture | 49 |
| Food industry | 30 |
| Forestry | 6 |
| General | 387 |
| Geophysics | 1 |
| Government, administration and public services | 24 |
| Health care | 114 |
| Hobbies and pastimes | 35 |
| Human rights activism | 26 |
| Immigration and citizenship | 22 |
| Industry | 866 |
| Information technology | 927 |
| Insurance | 37 |
| International law | 1 |
| International trade | 17 |
| Investment | 5 |
| Isolation | 9 |
| Labor law | 44 |
| Labor organization | 1 |
| Law | 420 |
| Leather | 5 |
| Life sciences | 147 |
| Lighting other than cinema | 26 |
| Magnetics | 6 |
| Marketing | 52 |
| Materials science | 250 |
| Mathematics | 76 |
| Mechanic engineering | 780 |
| Medical | 177 |
| Metallurgy | 386 |
| Microsoft | 205 |
| Mineral products | 5 |
| Mining | 1 |
| Municipal planning | 32 |
| Natural resourses and wildlife conservation | 19 |
| Natural sciences | 175 |
| Nuclear and fusion power | 3 |
| Nuclear physics | 14 |
| Obsolete / dated | 12 |
| Oil / petroleum | 5 |
| Patents | 163 |
| Pharmacy and pharmacology | 10 |
| Physical sciences | 27 |
| Physics | 4 |
| Politics | 85 |
| Power electronics | 20 |
| Power lines | 38 |
| Power system protection | 12 |
| Procedural law | 16 |
| Radio | 22 |
| Research and development | 4 |
| Satellite communications | 8 |
| Scientific | 12 |
| Security systems | 1 |
| Semiconductors | 10 |
| Social science | 58 |
| Sociology | 4 |
| Statistics | 245 |
| Sugar production | 1 |
| Taxes | 36 |
| Technology | 138 |
| Telecommunications | 7 |
| Telephony | 9 |
| Textile industry | 12 |
| Trade unions | 2 |
| Transformers | 22 |
| Transport | 1006 |
| United Nations | 16 |
| Waste management | 2 |
| Wind Energy | 2 |
| Wood processing | 1 |
| Work flow | 36 |
