 |
| protective cover: 32 phrases in 15 subjects |
| Advertising | 1 |
| Agrochemistry | 1 |
| Astronautics | 4 |
| Construction | 3 |
| Dentistry | 5 |
| Ecology | 1 |
| Electronics | 1 |
| Energy industry | 1 |
| Geology | 1 |
| Military | 5 |
| Mining | 1 |
| Missiles | 1 |
| Natural resourses and wildlife conservation | 1 |
| Technology | 5 |
| Weapons of mass destruction | 1 |