 |
| |||
| pillar-and-room method; rib-and-pillar | |||
| камерно-столбовая система: 71 phrases in 6 subjects |
| Geology | 4 |
| Gold mining | 2 |
| Mining | 55 |
| Oil / petroleum | 1 |
| Oil and gas | 1 |
| Technology | 8 |
|
| |||
| pillar-and-room method; rib-and-pillar | |||
| камерно-столбовая система: 71 phrases in 6 subjects |
| Geology | 4 |
| Gold mining | 2 |
| Mining | 55 |
| Oil / petroleum | 1 |
| Oil and gas | 1 |
| Technology | 8 |