| Accounting | 42 |
| Accumulators | 2 |
| Agriculture | 246 |
| Animal husbandry | 4 |
| Antennas and waveguides | 1 |
| Art | 3 |
| Astronautics | 1 |
| Banking | 3 |
| Business | 4 |
| Cables and cable production | 1 |
| Chemistry | 162 |
| Coal | 10 |
| Commerce | 34 |
| Communications | 610 |
| Computer networks | 4 |
| Construction | 48 |
| Criminal law | 26 |
| Cultural studies | 8 |
| Customs | 4 |
| Data processing | 2 |
| Demography | 6 |
| Earth sciences | 138 |
| Economics | 178 |
| Education | 18 |
| Electric machinery | 13 |
| Electric motors | 8 |
| Electric traction | 9 |
| Electronics | 521 |
| Employment | 2 |
| Energy industry | 30 |
| English | 4 |
| Environment | 137 |
| Finances | 548 |
| Fish farming pisciculture | 34 |
| Food industry | 22 |
| Forestry | 44 |
| General | 558 |
| Government, administration and public services | 10 |
| Health care | 109 |
| Hobbies and pastimes | 8 |
| Human rights activism | 62 |
| Immigration and citizenship | 35 |
| Industry | 288 |
| Information technology | 447 |
| Insurance | 48 |
| International law | 3 |
| International trade | 14 |
| Isolation | 12 |
| Labor law | 35 |
| Law | 454 |
| Leather | 1 |
| Life sciences | 66 |
| Lighting other than cinema | 3 |
| Magnetics | 4 |
| Marketing | 80 |
| Materials science | 118 |
| Mathematics | 30 |
| Mechanic engineering | 96 |
| Medical | 117 |
| Metallurgy | 196 |
| Mexican | 3 |
| Microsoft | 186 |
| Municipal planning | 3 |
| Natural resourses and wildlife conservation | 2 |
| Natural sciences | 65 |
| Nuclear physics | 3 |
| Obsolete / dated | 28 |
| Oil / petroleum | 2 |
| Patents | 186 |
| Pharmacy and pharmacology | 21 |
| Physical sciences | 3 |
| Physics | 5 |
| Politics | 106 |
| Polygraphy | 2 |
| Power electronics | 1 |
| Power lines | 10 |
| Power system protection | 7 |
| Private international law | 1 |
| Procedural law | 26 |
| Radio | 18 |
| Radiology | 3 |
| Rail transport | 14 |
| Reliability | 9 |
| Religion | 1 |
| Research and development | 3 |
| Satellite communications | 2 |
| Scientific | 6 |
| Scuba diving | 1 |
| Security systems | 2 |
| Semiconductors | 1 |
| Social science | 100 |
| Sociology | 2 |
| Sound recording | 4 |
| Statistics | 116 |
| Sugar production | 1 |
| Taxes | 39 |
| Technology | 89 |
| Telecommunications | 13 |
| Telegraphy | 16 |
| Textile industry | 13 |
| Thermal Energy | 2 |
| Trade unions | 10 |
| Transformers | 5 |
| Transport | 406 |
| United Nations | 5 |
| Vacuum tubes | 2 |
| Video recording | 2 |
| Waste management | 2 |
| Welding | 1 |
| Wind Energy | 1 |
| Wood processing | 2 |
| Work flow | 39 |
