 |
| |||
| compound classification | |||
| composite classification | |||
| multiple cross-classification | |||
| составная классификация: 6 phrases in 2 subjects |
| Airports and air traffic control | 1 |
| Librarianship | 5 |
|
| |||
| compound classification | |||
| composite classification | |||
| multiple cross-classification | |||
| составная классификация: 6 phrases in 2 subjects |
| Airports and air traffic control | 1 |
| Librarianship | 5 |