 |
| nitrogen compound: 16 phrases in 10 subjects |
| Agriculture | 1 |
| Ecology | 1 |
| Firefighting and fire-control systems | 1 |
| Makarov | 3 |
| Mathematics | 1 |
| Oil / petroleum | 1 |
| Oil and gas | 4 |
| Oil processing plants | 1 |
| Rail transport | 1 |
| Trade classification | 2 |
|
| nitrogen compound: 16 phrases in 10 subjects |
| Agriculture | 1 |
| Ecology | 1 |
| Firefighting and fire-control systems | 1 |
| Makarov | 3 |
| Mathematics | 1 |
| Oil / petroleum | 1 |
| Oil and gas | 4 |
| Oil processing plants | 1 |
| Rail transport | 1 |
| Trade classification | 2 |