oil sludge: 29 phrases in 11 subjects |
Agriculture | 1 |
Armored vehicles | 2 |
Caspian | 2 |
Chemistry | 1 |
Food industry | 2 |
Natural resourses and wildlife conservation | 2 |
Oil / petroleum | 7 |
Oil and gas | 2 |
Oil and gas technology | 1 |
Oil processing plants | 2 |
Technology | 7 |